This creamy potato bake with French onion soup mix is the kind of dish that arrives at the table warm and confident, immediately drawing everyone in. I first made it on a rainy evening when I wanted something comforting but a little more elegant than mashed potatoes. It quickly became a favorite because it combines familiar pantry staples with a glossy, savory cream sauce and a golden cheese crust that everyone fights for. The texture is utterly satisfying: thin, tender potato slices that cradle a silky, onion-scented cream and finish with a slightly crisp, cheesy top.

I discovered this combination after adapting a family casserole and swapping broth and thin slices for a richer cream base and the convenience of a French onion soup packet. What makes it special is how straightforward it is — no roux, no fuss — yet the result tastes like you spent all afternoon on it. The aromatic onion mix infuses the cream, so each bite carries that classic sweet-savory onion note. It’s a great make-ahead dish for gatherings, and it pairs beautifully with a crisp green salad or roasted vegetables for a complete meal.

Ingredients

• Potatoes: Use about 4.4 pounds (2 kg) of starchy or all-purpose potatoes, peeled, and thinly sliced for the ideal tender layers. Yukon Gold or Russet both work well; Yukon Gold keeps a silkier texture while Russets absorb flavors beautifully.
• Heavy cream: Approximately 2 1/2 cups (20 fl oz or 600 ml) of heavy cream provides richness and sets into a silky sauce. Choose a full-fat cream labeled heavy or whipping cream for best texture.
• French onion soup mix: One 1.4 oz packet (about 40 g) adds concentrated onion, salt, and herbs — a convenient flavor base. If using a low-sodium brand, you may need less added salt later.
• Tasty cheese (cheddar-style): About 9 oz (250 g), grated; this melts into a golden, slightly crisp topping. Choose a flavorful, mature variety for the best finish.
• Salt and pepper: A light seasoning of kosher salt and freshly ground black pepper to taste; add carefully because the soup mix and cheese contribute saltiness.

Instructions

Preheat the oven: Set your oven to 338°F (170°C) to allow gentle, even baking. A lower temperature helps the cream infuse the potato slices without boiling over; position the rack in the center for the most even heat. Slice the potatoes: Using a mandolin set to a thin setting, or a sharp knife, slice the peeled potatoes into 1/8 to 1/16-inch (about 2–3 mm) pieces. Aim for uniform thickness so they cook at the same rate; uneven slices lead to some pieces overcooked while others remain firm. Layer the potatoes: Arrange the slices in an even layer in a 9x13-inch (23x33 cm) baking dish, slightly overlapping like shingles. Build up honest layers until the dish is filled; don’t compact them too tightly — a bit of separation allows the cream to circulate and coat each slice. Make the cream mixture: Whisk together 2 1/2 cups (20 fl oz) heavy cream and the 1.4 oz packet of French onion soup mix until fully dissolved. Taste a small spoonful and adjust only if needed; the packet usually provides sufficient seasoning. Pour and cover: Pour the cream mixture evenly over the layered potatoes, tipping the dish gently to let the liquid settle between layers. Cover tightly with aluminum foil to trap steam and prevent too-rapid browning. Bake until tender: Bake covered for 1 hour 30 minutes (90 minutes), then check for tenderness by inserting a paring knife into the center; it should slide in without resistance. If still firm, return to the oven and test every 10–15 minutes. Add cheese and finish: Remove the foil, sprinkle 9 oz (250 g) grated cheese evenly over the top, and return to the oven uncovered for 10–15 minutes until the cheese melts, becomes bubbly, and develops light golden spots. Let rest 5 minutes before serving so the layers set slightly.

Storage Tips

Allow the dish to cool to near room temperature before storing. For short-term storage, cover tightly and refrigerate for up to 3 days. For longer storage, portion into airtight freezer-safe containers and freeze for up to 3 months. When reheating from chilled, cover with foil and warm at 325°F (160°C) until heated through, about 20–30 minutes depending on portion size; remove foil for the last 5–10 minutes to refresh the cheese crust. Thawed frozen portions reheat similarly but may need an extra 10–15 minutes. Look for bubbling interior and evenly warmed center as quality indicators.

Ingredient Substitutions

If you prefer a lighter version, substitute half-and-half for heavy cream, though expect a thinner sauce and somewhat less richness. For a dairy-free adaptation, replace cream with a full-fat coconut milk and use dairy-free cheese — note this will alter flavor significantly and move away from classic onion-cream notes. Swap the French onion packet for 2 cups of caramelized onions plus 1 tsp onion powder for a fresher onion flavor; reduce added salt accordingly. Use Gruyère, fontina, or a sharp cheddar in place of tasty cheese to vary the melting and flavor profile.

Serving Suggestions

Serve this bake as a hearty side for roasted meats, grilled sausages, or a simple pan-seared fish. For a lighter meal, pair with a crisp, acidic salad of arugula, lemon, and shaved fennel to cut through the richness. Garnish with chopped chives or parsley to add color and a fresh herbal note. For holiday tables, place the dish in the center and offer complementary sides like glazed carrots and green beans with toasted almonds; the creamy layers balance sweet and savory courses beautifully.

Cultural Background

The layered potato bake is a beloved form across many cuisines, from French gratins to Scandinavian dauphinoise. The addition of a French onion soup packet is a contemporary shortcut inspired by classic French onion flavors — caramelized onions, beefy-sweet depth, and dried herbs — concentrated into a convenient mix. While the technique nods to French gratin methods, this version simplifies the process for home cooks while keeping the savory backbone intact. It’s a practical example of how traditional flavors can be adapted into modern, time-saving preparations.

Seasonal Adaptations

In winter, add chopped roasted garlic and a pinch of nutmeg to the cream for warming depth. In spring, fold in a layer of thinly sliced leeks or blanched asparagus tips for freshness. For autumn, stir in roasted mushrooms or a handful of wilted kale between layers. During summer barbecues, keep the preparation light by using sharper cheese and topping with fresh herbs like tarragon or chives just before serving to add brightness.

Meal Prep Tips

Assemble the dish up to 24 hours ahead and keep covered in the refrigerator; allow it to sit at least 30 minutes on the counter before baking so it comes closer to room temperature and cooks more evenly. If you’re transporting it, assemble in an oven-safe disposable pan and bake on arrival. For portion-controlled meal prep, divide into individual ramekins, cover tightly, and store in the fridge; these reheat quickly and make convenient single-serve lunches.

This creamy potato bake is a reliable, crowd-pleasing dish that blends simplicity with comforting, layered flavor. Make it your own with small swaps, and enjoy how accessible it makes indulgent home cooking.