01 - Set oven to 375°F. Lightly grease a large baking dish or line with parchment paper.
02 - Lay bread slices in the prepared dish forming a single layer.
03 - In a mixing bowl, mash avocados with lemon juice, sea salt, and black pepper until mostly smooth yet slightly chunky.
04 - Distribute mashed avocado evenly across all bread slices.
05 - With a spoon, create a shallow well in the center of each slice.
06 - Carefully crack one egg into each prepared well, leaving yolks intact.
07 - Scatter halved cherry tomatoes and crumbled feta cheese over bread.
08 - Drizzle olive oil on top and sprinkle with red pepper flakes if desired.
09 - Transfer dish to oven. Bake for 20 to 25 minutes, until egg whites are set and yolks reach desired consistency.
10 - Remove from oven and garnish with chopped fresh chives before serving immediately.