Preheat the oven to 350°F.

In a large skillet over medium heat, heat the olive oil.

Sauté the onion and garlic until the onion is slightly translucent, about 5 minutes.

Add the mushrooms, and cook for another 5 to 10 minutes.

Stir in the bell pepper.

Remove the skillet from the heat.

In a medium bowl, whisk the eggs together.

Set aside.

Pour some of the egg mixture into each bacon-lined muffin well, and then spoon the sautéed veggie mixture into each one.

Bake for 25 minutes, or until the eggs are firm, and serve.