This oven baked 4-ingredient sheet pan French onion pasta is the kind of dinner you make once and then can’t stop thinking about. My brother threw it together for me on a busy weeknight, and it tasted like a cozy French onion soup collided with cheesy baked pasta—all done on one pan. It leans on a jar of French onion soup or concentrated French onion base to keep the ingredients list short, but still gives you those deeply caramelized onions, brothy flavor, and melty Gruyere over rigatoni. It’s perfect for nights when you want something comforting and homemade without a lot of fuss or dishes.
Serve this rich, cheesy French onion pasta with a simple green salad dressed in a tangy vinaigrette to balance the sweetness of the onions and richness of the cheese. Warm, crusty bread or garlic toast is lovely for scooping up any extra sauce and onions from the pan. A side of roasted green beans or steamed broccoli works well for families and adds a bit of color to the plate. For adults, a glass of dry white wine or a light red pairs nicely, while the kids might enjoy sparkling water with lemon to cut through the richness.
Oven Baked 4-Ingredient Sheet Pan French Onion Pasta
Servings: 4

Ingredients
12 oz dry rigatoni pasta (or other short, tube-shaped pasta)
2 large yellow onions, thinly sliced
1 1/2 cups prepared French onion soup or French onion soup base (concentrated, see note)
2 cups shredded Gruyere cheese, divided
Directions
Preheat your oven to 400°F (200°C). Lightly grease a dark metal sheet pan with a little oil or nonstick spray to help prevent sticking and make cleanup easier.
Thinly slice the onions from root to tip. Spread the sliced onions out evenly over the sheet pan, breaking them up with your fingers so they’re not clumped together. This helps them caramelize more evenly in the oven.
Pour 1 cup of the prepared French onion soup (or diluted French onion soup base, according to package directions) over the onions and gently toss with clean hands or tongs so they’re lightly coated. Spread them back into an even layer.
Place the sheet pan on the middle rack and roast the onions for 18–22 minutes, stirring once halfway through, until they are soft, golden brown in spots, and smell sweet and deeply savory. Watch the edges so they don’t burn; if they start to darken too quickly, stir and spread them back out.
While the onions roast, bring a large pot of salted water to a boil. Cook the rigatoni for about 2 minutes less than the package directions for al dente (the pasta will finish cooking in the oven). Drain well and return the pasta to the pot.
When the onions are caramelized, carefully remove the hot sheet pan from the oven and reduce the oven temperature to 375°F (190°C). Use a spatula to gently push the onions into a slightly more compact layer, leaving just enough room around the edges for the pasta.
Add the caramelized onions and any pan juices to the pot of drained pasta. Pour in the remaining 1/2 cup French onion soup and add 1 1/2 cups of the shredded Gruyere. Toss until everything is evenly combined and the cheese starts to melt and cling to the pasta. If it looks a little dry, you can splash in a tablespoon or two of hot water to help it coat.
Return the pasta mixture to the same sheet pan, spreading it out in an even layer so you get lots of surface area for browning. Sprinkle the remaining 1/2 cup Gruyere evenly over the top, making sure some cheese hits the edges for those crispy bits.
Bake the sheet pan pasta at 375°F (190°C) for 12–15 minutes, or until the cheese is melted, bubbling, and lightly browned in spots and the pasta is tender but not mushy.
For extra color on top, you can move the sheet pan under the broiler for 1–2 minutes at the end, watching closely so the cheese doesn’t burn. Remove from the oven and let the pasta rest on the counter for 5 minutes to set slightly, which makes it easier to scoop.
Serve the French onion pasta straight from the sheet pan, making sure each portion gets plenty of caramelized onions and gooey Gruyere on top. Store leftovers in a covered container in the refrigerator for up to 3 days and reheat in the oven or microwave until piping hot.
Variations & Tips
If your family prefers milder onion flavor, use one onion instead of two and slice it a bit thicker so it doesn’t cook down quite as intensely. For kids who are picky about onion texture, you can roughly chop the roasted onions after they come out of the oven so they blend into the pasta more. If Gruyere is hard to find or a little pricey, Swiss cheese or a mix of Swiss and mozzarella will give you a similar melty, nutty effect. To stretch the meal, you can stir in cooked shredded rotisserie chicken or browned ground beef after you toss the pasta with the onions and cheese—just keep in mind that this adds ingredients beyond the base
4. For a slightly lighter version, use whole-wheat pasta and reduce the cheese by 1/2 cup, adding a splash more broth to keep things saucy. If you’re using a concentrated French onion soup base, follow the package directions to make the 1 1/2 cups liquid, and taste before adding salt anywhere else, as these bases can be quite salty. Food safety tips: Always cook the pasta in fresh, clean water and drain with clean equipment. If you add any meat, make sure it’s fully cooked to a safe internal temperature (165°F/74°C for poultry) before mixing it into the pasta. Cool leftovers within 2 hours of baking and refrigerate promptly in shallow containers. Reheat leftovers to at least 165°F (74°C) before serving. Keep children away from the hot sheet pan when it comes out of the oven, as the metal stays very hot and can cause burns.