Mix lump crabmeat with a silky homemade mayonnaise for the perfect summer salad, and then set it out with makings for sandwiches.
Stir together crab, mayonnaise, and chopped chervil. Season with lemon juice, salt, and pepper. Top with chervil sprigs.
Arrange tomatoes and lettuces on a platter. Season with salt and pepper, and drizzle with oil. Sprinkle with basil. Serve with crab salad and bread for assembling sandwiches.