8 Servings * may need extra canned tomato sauce for topping
1. Heat the olive oil in a large soup pot over medium heat. When the oil shimmers, add the onion and season with salt and pepper. Cook 5 minutes or until the onion is fragrant and beginning to caramelize. Add the bell pepper, garlic, sausage, and beef, brown all over, breaking up the meat as you go, about 10 minutes.
2. Add the tomatoes, tomato paste, oregano, bay leaves, milk, and 1 cup of water. Season with salt and pepper. Stir to combine. Cook over medium for 30 minutes, until the sauce has thickened slightly. Or cook, covered, for up to 3 hours over low heat, stirring occasionally. The longer you can cook, the more flavorful. Remove the bay leaves and discard. If your sauce seems thick, add 1/2 cup additional water to thin.
3. In a medium bowl combine the ricotta and pesto.
4. Preheat the oven to 375 degrees F. Grease a 9x13 inch pan. Spread 1/4 of the Bolognese sauce onto the bottom of the dish. Top with 3-4 lasagna sheets. Spread with 1/2 the ricotta cheese mixture, another 1/4 of the Bolognese sauce, and half of the provolone. Place another 3-4 lasagna noodles on top. Then top with the remaining ricotta cheese mixture, another 1/4 of the Bolognese sauce, and the remaining provolone. Add the remaining lasagna noodles and pour the remaining Bolognese sauce over top. Top with mozzarella and parmesan cheese. Bake uncovered for 45 minutes or until the top has bubbled up and browned a bit. Let stand 10 minutes before serving.