Hearty Lasagna Casserole

Preheat your oven to the desired temperature of 375 degrees F (or 190 degrees C). Position a rack in the center of your oven, roughly 10 inches away from the heat source.

Next, fill a large pot with salted water and bring it to a rolling boil. Add pasta shells and cook, stirring occasionally, until they're almost tender, taking around 7 minutes. Drain the pasta in a colander and return it to the pot.

In a separate pan, heat the remaining 3 tablespoons of oil over medium-high heat. Add sirloin and sausage to the pan and cook, undisturbed, until the bottom side is lightly browned, approximately 6 minutes. Stir occasionally and continue to cook, breaking up the meat with a wooden spoon until it's fully cooked through, around 4 minutes.

Reduce the heat to medium and add onion and garlic to the pan. Cook, stirring frequently, until they're softened, taking about 4 minutes.

Stir in marinara sauce, basil, and crushed red pepper to the pan. Remove the ragu from heat.

In a separate bowl, combine ricotta, Parmigiano-Reggiano, cream, and salt. Mix everything together until it's well combined.

To assemble the lasagna, spread about 2 cups of the ragu in the bottom of a 13- x 9-inch baking dish. Spoon half of the pasta over the sauce, followed by half of the ricotta mixture and a sprinkle of 1 cup mozzarella cheese. Repeat this process, starting with the pasta, then the remaining ragu, and finally the remaining ricotta mixture. Top it all off with the remaining 1/2 cup mozzarella cheese.

Cover the lasagna with a large sheet of aluminum foil that's been lightly sprayed with cooking spray to prevent the cheese from sticking.

Bake in your preheated oven for 30 minutes, then remove the foil and increase the oven temperature to broil. Position a rack in the center of your oven, roughly 10 inches away from the heat source and preheat for 5 minutes. Return the baking dish to the oven and broil until the cheese is browned in spots, taking 5 to 8 minutes.