01 - Bring a medium saucepan of water to a gentle boil. Carefully lower in the eggs and simmer for 6–7 minutes for soft-boiled yolks. Transfer eggs to an ice bath and let cool for 2 minutes, then peel carefully.
02 - While eggs cook, toast the bread slices in a toaster or on a grill until golden and crisp throughout.
03 - In a small bowl, whisk together olive oil, lemon juice, Dijon mustard, salt, and pepper until emulsified and well combined.
04 - In a large bowl, toss mixed greens and cherry tomatoes with half of the dressing until lightly coated.
05 - Arrange toasted bread on serving plates. Top each toast with sliced avocado and a portion of dressed greens.
06 - Halve the soft-boiled eggs and place on top of each plate. Drizzle with remaining dressing and garnish with chopped chives and flaky sea salt. Serve immediately while eggs are warm.