Arrange the sliced vegetables in separate piles on 2 large rimmed baking sheets. In a small bowl, whisk the vinegar with the olive oil and season with salt and pepper. Drizzle the dressing over the vegetables and toss each pile separately. Let stand for at least 15 minutes or up to 1 hour.
Meanwhile, bring a medium saucepan of water to a boil. Carefully lower the eggs into the saucepan and reduce the heat to moderate. Simmer the eggs for 6 minutes. Pour off the hot water and gently shake the eggs in the pan to crack the shells. Fill the pan with cold water and let stand for 1 minute. Carefully peel the eggs. Reheat the peeled eggs for 2 minutes in 2 inches of simmering water. Drain and pat dry then halve the eggs.
Arrange the vegetables on plates and top with the toasts and the soft-boiled eggs. Sprinkle the eggs and salads with fleur de sel and serve.