Ratatouille Lasagna

Name: Ratatouille Lasagna
Ingredients: 2-4 tablespoons extra virgin olive oil, divided; 1 medium yellow onion, chopped; 2 cloves garlic, minced; 1 medium eggplant (about 1 lb.), cut into 1/2 cubes; 2 medium zucchini, cut into 1/2 cubes; 1 yellow bell pepper, seeded and chopped; 1 red bell pepper, seeded and chopped; (2) 28 ounce cans crushed tomatoes; 1 tablespoon tomato paste; 1 tablespoon sugar; 1 bay leaf; 3 sprigs fresh thyme or 1 teaspoon dried; 12 leaves fresh basil, chopped, plus more for garnish; For the lasagna:; (1) 13.25 ounce box lasagna; (1) 15 ounce container ricotta cheese; 2 cups grated mozzarella