Steak and baby potatoes sealed in foil with garlic butter and rosemary, cooked until the potatoes are tender and the steak is still pink in the middle. Each packet is a complete dinner, and there is no pan to wash.
The one real challenge is that potatoes need about twenty-five minutes and steak needs about eight. Solving that mismatch is the entire technique, and it is why so many foil packet recipes produce either raw potatoes or grey steak.
Fifteen minutes of prep and about thirty in the oven or on the grill.
Why You Will Love This Recipe
Nothing to wash. The packet is the cooking vessel and the serving dish.
It cooks anywhere. Oven, grill, or campfire, with the same timing.
Individual portions. Each person gets their own packet, and each can be cooked to a different doneness.
The garlic butter becomes the sauce. Steak juices and butter pool in the base of the packet.
It travels. Assemble at home, cook at a campsite or on a grill at someone else’s house.
Recipe Overview
Prep time: 15 minutes
Cook time: 30 to 35 minutes
Rest time: 5 minutes
Total time: About 55 minutes
Yield: 4 packets
Difficulty: Easy
Best for: Grilling season, camping, weeknight dinners, date night, low-cleanup meals
Ingredients
For the Packets
• 1 1/2 pounds (680 g) sirloin or ribeye steak, cut into 2-inch pieces
• 1 1/2 pounds (680 g) baby potatoes, halved or quartered
• 1 teaspoon kosher salt
• 1/2 teaspoon coarsely ground black pepper
• 4 sprigs fresh rosemary
• Heavy-duty aluminium foil
For the Garlic Butter
• 6 tablespoons unsalted butter, melted
• 6 cloves garlic, finely minced
• 1 tablespoon Worcestershire sauce
• 1 teaspoon dried thyme
• 1/2 teaspoon smoked paprika
• 1/2 teaspoon black pepper
• 1/2 teaspoon kosher salt
To Finish
• 2 tablespoons chopped fresh parsley
• Flaky sea salt
Choosing the Right Steak and Potatoes
Sirloin is the practical choice. It has enough flavour, stays tender at medium, and costs considerably less than ribeye.
Ribeye is the richer option. Its marbling protects it from drying out, which matters in a sealed packet.
New York strip works well and sits between the two on price.
Avoid tenderloin. It is very lean and has little to protect it in a moist environment, so it goes from pink to grey quickly.
Avoid stew beef and chuck. Both need hours of low heat and will be tough after thirty minutes.
Baby potatoes are essential. Halved or quartered they cook in the same window the steak can tolerate. Full-size potatoes cut into chunks take considerably longer.
Yukon Gold and red baby potatoes both work. Cut them to a uniform size, no larger than about an inch.
Why the Potatoes Get a Head Start
This is the difference between a foil packet that works and one that disappoints in one direction or the other.
Potatoes need 25 to 30 minutes. Even cut small, raw potato needs that long at 400°F to become tender.
Steak needs 8 to 12 minutes. Sealed in foil with butter it cooks quickly, and beyond that it turns grey and dry.
Cooking them together for the full time ruins the steak. This is the most common outcome, and it is why many people conclude foil packet steak is a bad idea.
Two solutions work. Either par-cook the potatoes for 10 minutes before assembling, or seal the potatoes alone for the first 15 minutes and add the steak partway through.
The parboiling method is easier. Ten minutes in boiling salted water, drained and dried, and then everything cooks together for about 20 minutes.
How to Make Steak and Potato Foil Packets
Step 1: Par-cook the potatoes
Bring a pot of salted water to a boil and cook the halved potatoes for 10 minutes, until just starting to soften but not fully tender.
Drain thoroughly and let them steam dry for 2 minutes.
Drying them matters. Wet potatoes release water into the packet and the steak steams rather than browning.
Step 2: Preheat
Preheat the oven to 425°F (220°C), or heat a grill to medium-high.
Step 3: Make the garlic butter
Whisk together the melted butter, minced garlic, Worcestershire, thyme, smoked paprika, black pepper, and salt.
Step 4: Cut the steak
Cut the steak into 2-inch pieces and pat them completely dry.
Uniform pieces cook evenly. Mixed sizes leave you with some overcooked and some rare in the same packet.
Step 5: Toss everything
In a large bowl, toss the par-cooked potatoes and the steak pieces with about three quarters of the garlic butter, plus the salt and pepper.
Step 6: Build the packets
Tear four large sheets of heavy-duty foil, about 18 inches each. Divide the steak and potatoes between them, keeping each portion in a single layer.
Lay a rosemary sprig on top of each and drizzle with the remaining garlic butter.
Use heavy-duty foil, or double up regular foil. Standard foil tears at the folds and the butter leaks out.
Step 7: Seal
Bring the long sides of the foil together above the food and fold them over twice, then fold in each end twice to seal completely.
Leave some air space inside. The packet needs room for steam to circulate. A tightly wrapped packet cooks unevenly.
Step 8: Cook
Place the packets on a baking sheet and cook for 20 to 25 minutes in the oven, or 15 to 18 minutes on a covered grill.
For medium-rare steak, check at 18 minutes. The steak should read 130°F at the centre of the largest piece.
Step 9: Rest and open
Let the packets rest for 5 minutes before opening.
Open them away from your face. The trapped steam is genuinely hot.
Scatter with parsley and flaky salt, and spoon the butter from the base over everything.
Tips for the Best Foil Packets
Par-cook the potatoes. The single decision that makes this recipe work.
Use heavy-duty foil. Regular foil tears and leaks butter onto the pan or into the fire.
Dry the steak and potatoes. Wet ingredients steam and the steak comes out grey.
Keep everything in a single layer. Stacked pieces cook unevenly inside a sealed packet.
Leave air space when sealing. The packet should puff slightly, not be moulded tight to the food.
Common Mistakes to Avoid
Adding raw potatoes with the steak. Either the potatoes are hard or the steak is overcooked. There is no timing that satisfies both.
Cutting potatoes too large. Anything over an inch will not cook through in time.
Using thin foil. It tears at the folds and everything leaks.
Sealing the packet too tightly. Steam needs somewhere to circulate.
Opening the packet immediately. Five minutes of rest keeps the juices in the steak rather than on the foil.
Easy Variations
• With mushrooms. Add 8 ounces of halved cremini mushrooms with the steak.
• Steakhouse. Add a slice of compound butter with blue cheese on top of each portion before sealing.
• With green beans. Add a handful of trimmed green beans to each packet.
• Cajun. Season with Cajun spice instead of thyme and paprika.
• Chicken version. Use 1 1/2 pounds of chicken thigh pieces and cook for 25 to 30 minutes to 175°F.
• Campfire. Cook on coals, not flames, for 20 to 25 minutes, turning once.
What to Serve With Them
They are a complete meal, so anything else is optional.
A sharp green salad with vinaigrette is the best addition, since the packet is rich and starchy already.
Crusty bread is worth having for the garlic butter left in the foil.
Grilled corn or a simple slaw work well at a cookout.
Make-Ahead and Storage
Make-ahead: Assemble the packets fully, sealed, up to 24 hours in advance and refrigerate. Add about 5 minutes to the cooking time from cold. This makes them ideal for camping.
The garlic butter can be made up to 5 days ahead.
Refrigerator: Store cooked leftovers in an airtight container for up to 3 days.
Freezer: Not recommended. The potatoes turn grainy and the steak texture suffers.
To reheat: Warm gently in a covered pan over low heat, or at 300°F for 12 minutes. High heat overcooks steak that is already cooked through.
Frequently Asked Questions
Why were my potatoes still hard?
They were not par-cooked, or they were cut too large. Ten minutes of boiling first solves it.
What steak cut is best?
Sirloin for value, ribeye for richness. Avoid tenderloin and any braising cut.
Can I cook these on a grill?
Yes. Medium-high heat with the lid closed, 15 to 18 minutes, turning once.
Can I make them ahead?
Yes, assemble up to 24 hours ahead and refrigerate sealed. Add 5 minutes to the cook time.
How do I get medium-rare steak?
Check at 18 minutes with a thermometer inserted through the foil into the largest piece. Pull at 130°F.
Do I need heavy-duty foil?
Strongly recommended. Otherwise use two layers of regular foil.
Nutrition Information
Approximate values per packet, based on 4 servings:
• Calories: 585
• Total fat: 33 g
• Saturated fat: 16 g
• Carbohydrates: 31 g
• Fiber: 4 g
• Protein: 40 g
• Sodium: 690 mg
Nutrition is estimated and will vary with cut and portion sizes.