2 tablespoons (30 milliliters) olive oil, plus more for greasing muffin tins
1 red bell pepper, seeded and diced
1 green bell pepper, seeded and diced
1 red onion, diced
1 garlic clove, minced
1/4 cup (60 milliliters) whole milk
1/2 teaspoon (2.5 milliliters) pepper
1 cup (240 milliliters) shredded Gouda
1/4 cup (60 milliliters) chopped fresh chives, for garnish
Preheat oven to 350 F (175 C).
Thoroughly grease eight cups in a muffin tin. Place two slices of prosciutto overlapping into each cup. Press down and around the sides so that the prosciutto lines the cup, with some of the prosciutto coming above the cup. Bake the prosciutto in the oven for eight minutes. Remove and let cool at room temperature.
In the meantime, in a small pan, heat olive oil over medium heat, then add red pepper, green pepper, and red onion and sauté until soft. Add garlic and cook for one minute. Remove from heat and set aside.
In a bowl, whisk together eggs, milk, and pepper. Stir in 3/4 of the shredded Gouda, then stir in the sautéed vegetables. Using a small ladle, ladle the egg mixture evenly into the eight cups, making sure the mixture is stirred so that each cup gets an equal amount of the sautéed vegetables and cheese. Top each cup with some of the remaining Gouda, then put the tin in the oven to bake for eight to ten minutes, or until the eggs are set. Remove from oven and garnish with chopped chives.