3 vegetable gratin vegetarian Recipes

butter, dijon mustard, beer, double cream, vegetarian cheddar cheese, potatoes, thinly sliced, turnips, thinly sliced, sweet potatoes, thinly sliced, caraway seeds

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