Brown the Meat:Heat a large skillet over medium-high. Add the ground beef and sausage. This meat is broken up as it cooks with a wooden spoon. You then dispose of excess grease after it is cooked. (Optional) Place the browned meat into a food processor and pulse 3-4 times. Chop it very finely, then add it to a bowl and set aside.
Sauté the Vegetables:In the same skillet, heat a little olive oil over medium-high. When hot, throw in the garlic and sauté 30 seconds or until fragrant, stirring constantly. Add the onion, spinach and bell pepper; cook until vegetables are soft, about 2-3 minutes. Pour into a food processor. Pulse several times until nearly pureed. Return to the skillet.
Red Sauce Preparation:Add the whole peeled tomatoes to the skillet, crushing them into the sauce, along with the tomato sauce. Toss to combine, then season with Italian herbs, salt and pepper to taste. Cover the skillet and let the sauce simmer on low heat for about 20-30 minutes, stirring occasionally. Fold in the reserved crumbled meat and fresh basil just before using the red sauce in the lasagna.
Pasta Preparation:Boil the pasta in a large pot of lightly salted water until it's al dente. Reserve 1 cup of the pasta cooking water and then drain the pasta and set it aside.
While the red sauce is cooking, cook the lasagna noodles. Cook for half of the time on the package. Then drain in a very large colander and lightly drizzle with olive oil to avoid sticking. Skippable for those using no-boil noodles.
Béchamel Sauce:Melt butter over medium heat in a medium saucepan or large skillet. When butter has melted, add flour to whisk, and cook over medium, stirring constantly for 2 minutes. Gradually add milk while continually whisking. Taste and adjust the seasoning with salt and pepper. Continue to cook over medium heat without stopping; repeatedly whisking to avoid burning, till thickened. This should be around 5-7 minutes. Prepare and preheat to assemble
Preheat the oven to 350°F (175°C). Grease with cooking spray a 9x13-inch baking dish. This will be the ultimate three-layer lasagna, so divide the sauces mentally into thirds, ready for each layer that will form the final dish.
Layer the Lasagna:Begin with 3 lasagna noodles on the bottom of the prepared dish. Spread a layer of red sauce over the noodles, followed by the béchamel sauce, and sprinkle Parmesan and mozzarella cheese over it, so everything goes to the sides. Leave another layer of noodles set aside, repeating the procedure with red sauce, béchamel, and cheeses. Cover the final layer of noodles with red sauce and béchamel and cheese.
Bake:Bake the lasagna for at least 40-50 minutes or until hot and bubbly. Let it rest at least 20 minutes before slicing.
Servings:Serve with garlic bread or homemade breadsticks and a refreshing green salad for a complete meal!