Preheat oven to 350°F. Grease a nonstick muffin tin with extra-virgin olive oil (use a brush or a lightly oiled paper towel).

Evenly divide the 2 cups diced red bell pepper and the ½ cup chopped scallions among the muffin cups.

In a large bowl, crack and whisk the 9 large eggs until combined.

Add the grated garlic clove, the heaping ½ teaspoon sea salt, and several grinds of freshly ground black pepper to the eggs; whisk to combine.

Sprinkle the 3 tablespoons all-purpose flour and the ¾ teaspoon baking powder over the egg mixture. Whisk until mostly smooth (a few small lumps are OK).

Divide the egg mixture evenly into the muffin cups over the peppers and scallions (about a scant ¼ cup per cup).

Sprinkle the ⅓ cup crumbled feta evenly over the filled cups.

Bake for 22 to 24 minutes, or until the eggs are set and the centers do not jiggle.

Let the muffins cool in the pan for a few minutes before removing; run a knife around each cup if needed and then remove to finish cooling or serve.