Three-Cheese-and-Herb Frittata Sandwiches - Master recipes

Ingredients

• 2 tbsp. unsalted butter -
• 2 tbsp. extra-virgin olive oil -
• 2 small onions -
• 1/2 tsp. thyme -
• 1 pinch crushed red pepper -
• 1 bay leaf -
• Kosher salt -
• Freshly ground pepper -
• 10 large eggs -
• 4 oz. crumbled fresh goat cheese -
• 1/2 c. Parmigiano-Reggiano cheese -
• c. finely chopped parsley -
• c. finely chopped chives -
• 1 c. shredded Gruyère cheese -
• 3 c. baby arugula -
• 1 1/2 tbsp. red wine vinegar -
• Homemade Bagels or store-bought bagels -
• Butter -
• 2 medium tomatoes -
• 12 slice prosciutto -
• 12 large basil leaves -