4 vegetarian onion tomato gratin Recipes

nonstick cooking spray or vegetable oil, onion, peeled,cut in half and thinly sliced, salt & freshly ground black pepper, red potatoes, peeled and sliced 1/8 inch thick, fresh thyme leaves or 1 tsp dried thyme, divided, ripe tomatoes, cored and cut into thin slices, garlic, peeled,thinly sliced, olive oil, white wine, vegetable broth (or more if needed), unsalted butter , optional

olive oil, onion, thinly sliced, garlic cloves, peeled and sliced, bay leaf, eggplant , cut into 1/2-inch pieces (about 3 cups), zucchini , halved lengthwise and cut into thin slices, red bell pepper , cut into slivers, tomatoes, coarsely chopped (about 1 1/4 cups), kosher salt, shredded fresh basil leaves, freshly ground black pepper, ziti, ricotta cheese, eggs, beaten, olive oil, grated parmesan, shredded cheddar

butter or 1 tbsp olive oil, onion, chopped, garlic, finely chopped, white beans or 1 (15 oz) can black beans, drained, vegetarian chicken broth, whole tomatoes , in tomato juice, basil, oregano, rosemary, cayenne pepper, fresh spinach, washed and dried, mozzarella cheese, shredded