Onion Gratin with Rosemary and Thyme

Ingredients

• 8 small or 6 medium-sized white, yellow, or Vidalia onions
• Olive oil, for brushing onions
• 1 tsp. finely minced fresh rosemary
• 2 T minced fresh thyme leaves
• 6 T mayo
• 1 T fresh squeezed lemon juice
• 1/2 tsp. Dijon mustard
• 1 cup Pizza cheese blend
• 3 T grated Pecorino-Romano cheese
• Fresh ground black pepper to taste
• 1/2 cup mayo
• 1 T + 1 tsp. fresh-squeezed lemon juice
• 3/4 tsp. Dijon mustard
• 1 1/2 cups Pizza cheese blend

Directions

1. Heat the oven to 450F/230C. Peel the onions, then slice them into 1/2 inch rounds. Coat a baking sheet with olive oil or non-stick spray, and set the onion slices on it in one layer. Brush or spray the tops with oil, then scatter the chopped fresh or dried herbs over them.
2. Roast the onions for 15 minutes. Pull the pan from the oven, and lower the heat to 375F/190C.
3. As the onions cook, stir the mayo, lemon juice, Dijon mustard, pizza cheese, Pecorino-Romano cheese, and black pepper together in a small bowl with a fork. It will not be smooth, and that is exactly what you want.
4. Coat either an 8″ x 10″ square baking dish or a 9″ x 13″ rectangular or oval casserole dish with olive oil or nonstick spray.
5. Transfer the roasted onions from the sheet pan into the prepared casserole dish with a turner, arranging them in layers. Spoon the topping over the onions and spread it around with a rubber scraper if needed. It does not need to blanket every single piece.
6. Bake the casserole at 375F/190C for 30-40 minutes, until the surface is browned and the onions are gently bubbling. Serve hot.