Toast the artisan bread slices until golden brown and slightly crisp.

In a small bowl, mash the ripe avocado with lemon juice, sea salt, and black pepper until mostly smooth but with some texture remaining.

Spread the smashed avocado evenly over the toasted bread slices.

Prepare for poaching: Fill a medium saucepan with about 3-4 inches of water. Add the white vinegar (if using). Bring the water to a gentle simmer (do not boil vigorously).

Carefully crack one egg into a small ramekin or bowl. Gently slide the egg into the simmering water. Repeat with the second egg, ensuring they have space between them.

Poach the eggs for approximately 3-4 minutes for a runny yolk, or slightly longer for a firmer yolk. The whites should be set but the yolk still liquid.

Using a slotted spoon, carefully remove the poached eggs from the water. Gently dab any excess water with a paper towel.

Place one poached egg atop each avocado-smashed toast. Sprinkle generously with smoked paprika, red chili flakes, sea salt, and freshly ground black pepper.

Garnish with chopped fresh cilantro or chives before serving immediately.