01 - Heat the oven to 375°F. Line a 12-cup muffin tin with paper liners or lightly grease each cup.
02 - In a large bowl, whisk together all-purpose flour, baking powder, baking soda, salt, and black pepper until well blended.
03 - In a separate bowl, beat the eggs, whole milk, and olive oil or melted butter until thoroughly combined.
04 - Pour the wet ingredients into the dry mixture. Stir gently until just combined, taking care not to overmix.
05 - Gently fold grated cheddar, crumbled feta, diced bell pepper, chopped greens, chives, and parsley into the batter until evenly distributed.
06 - Spoon the batter evenly into muffin cups, filling each to about three-quarters full.
07 - Bake for 22 to 25 minutes, or until muffins are golden brown and a toothpick inserted in the center comes out clean.
08 - Allow muffins to cool in the pan for 5 minutes before transferring to a wire rack. Serve warm or at room temperature.