This 5-ingredient oven classic rigatoni casserole is the kind of weeknight dinner that looks and tastes like you fussed all afternoon, but really comes together with a few pantry staples and one baking dish. You toss dry tube pasta straight into the pan with jarred sauce, frozen mixed vegetables, and a couple of fridge standbys, then let the oven do the rest. It’s cozy, colorful, and family-friendly—perfect for those nights when you want something homemade and comforting without hovering over the stove.
Serve this rigatoni casserole with a simple green salad (bagged lettuce, a handful of cherry tomatoes, and bottled dressing are just fine) and some warm bread or garlic toast for dipping into the saucy corners of the pan. A side of sliced apples or grapes works well for kids who like a little fruit with dinner. If you’re cooking for guests, add a quick platter of olives and cheese cubes while the casserole bakes, and finish the meal with store-bought cookies or brownies to keep everything easy but still feel special.
5-Ingredient Oven Rigatoni Vegetable CasseroleServings: 6
Ingredients
12 oz dry rigatoni or other tube pasta
1 (24 oz) jar marinara or pasta sauce
2 cups frozen mixed vegetables (carrots, peas, corn, green beans, or similar)
2 cups shredded mozzarella cheese, divided
2 cups water
1/2 tsp salt (optional, to taste)
Directions
Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch ceramic or glass baking dish with a little oil or nonstick spray if you’d like easier cleanup.
Scatter the dry rigatoni evenly across the bottom of the baking dish. It should look like a loose, single layer of uncooked tube pasta with some space between the pieces.
Sprinkle the frozen mixed vegetables evenly over and between the rigatoni, letting the colorful veggies fall down into the gaps so you can see them peeking through the tubes.
In a medium bowl or large measuring cup, whisk together the jar of marinara sauce and the 2 cups of water until well combined. Taste and stir in the optional 1/2 teaspoon salt if your sauce is on the mild side.
Pour the sauce-and-water mixture slowly and evenly over the pasta and vegetables, making sure to cover all the dry pasta. Gently press down any noodles that are sticking up so most of them are submerged in the liquid.
Sprinkle 1 cup of the shredded mozzarella evenly over the top. Cover the baking dish tightly with aluminum foil, tenting it slightly so the cheese doesn’t stick to the foil.
Bake covered for 35–40 minutes, until the pasta is mostly tender when you poke a piece with a fork and the sauce is bubbling around the edges. If the pasta still feels quite firm, re-cover and bake another 5–10 minutes.
Carefully remove the foil (watch for steam), then sprinkle the remaining 1 cup of mozzarella evenly over the top of the casserole.
Return the dish to the oven, uncovered, and bake for another 10–15 minutes, or until the cheese is melted, lightly golden in spots, and the casserole is bubbling in the center.
Let the casserole rest on the counter for 8–10 minutes before serving so it can thicken up a bit and is easier to scoop. Serve warm, making sure each portion gets plenty of pasta, vegetables, and cheesy topping.
Variations & Tips
For picky eaters, you can use a milder marinara (look for labels like “traditional” or “tomato & basil”) and choose frozen vegetables your family loves—peas and corn are usually kid favorites. If someone really dislikes mixed vegetables, swap them for just frozen peas or chopped spinach. To add protein without changing the 5-ingredient feel, you can stir in 1–2 cups of leftover cooked chicken, cooked Italian sausage, or a drained can of chickpeas along with the vegetables. For a little extra flavor, sprinkle dried Italian seasoning or garlic powder over the top with the first layer of cheese. If you prefer a creamier casserole, replace 1/2 cup of the water with milk or half-and-half. For a lighter version, use part-skim mozzarella and a tomato sauce that’s lower in sodium. Food safety tips: Make sure any added meats are fully cooked before mixing into the casserole, since the oven time here is mainly to cook the pasta and melt the cheese, not to cook raw meat. If you use frozen vegetables, there’s no need to thaw them first, but keep them frozen until you’re ready to assemble so they stay safe and don’t sit at room temperature. Bake until the casserole is bubbling hot in the center (at least 165°F/74°C if you’re checking with a food thermometer). Refrigerate leftovers within 2 hours of serving in shallow containers, and reheat only what you’ll eat to at least 165°F before enjoying again.
