01 - Bring a small saucepan of water to a gentle simmer. Add white vinegar.
02 - Crack each egg into a small bowl. Carefully swirl the water with a spoon to create a vortex, and gently slip one egg into the center.
03 - Poach each egg for about 3–4 minutes until the whites are set but the yolk is still runny. Remove with a slotted spoon and drain on paper towels.
04 - Meanwhile, mash the avocado in a bowl with a pinch of salt, pepper, and a squeeze of lemon juice if using.
05 - Spread the mashed avocado generously over the toasted bread slices.
06 - Top each toast with a poached egg.
07 - Sprinkle with red pepper flakes, everything bagel seasoning, or additional salt and pepper as desired.
08 - Serve immediately.