For best results, slice the radishes as thinly as possible. If you have a mandoline, this is the time to use it, but you can also slice them by hand (small ones are easiest to cut by hand). Chill the radishes and lemon juice at least 30 minutes, and keep in mind that the longer you chill them, the pinker they'll become.
2 cups thinly sliced radishes (about 1 pound)
1 tablespoon fresh lemon juice, divided
1/2 teaspoon salt, divided
8 large eggs
1/4 teaspoon freshly ground black pepper
2 tablespoons extra-virgin olive oil
3 tablespoons plain Greek-style fat-free yogurt
1 cup lump crabmeat, drained and shell pieces removed (about 5 ounces)
1/4 cup finely chopped celery (about 3 medium stalks)
1 teaspoon dry mustard
24 butter lettuce leaves
How to Make It
Combine radishes, 2 teaspoons juice, and 1/4 teaspoon salt in a bowl; toss. Cover and chill at least 30 minutes.
Place eggs in a medium saucepan, and cover with cold water to 1 inch above eggs; bring to a boil. Reduce heat, and simmer 10 minutes. Place eggs in ice water, and cool completely. Gently crack eggshells; peel under cold running water. Cut each egg in half lengthwise. Remove yolks. Press yolks through a sieve into a bowl. Set aside 1 tablespoon yolks. Combine remaining 1 teaspoon juice, remaining yolks, 1/4 teaspoon salt, and pepper in a bowl; gradually add oil, stirring well with a whisk until oil is incorporated. Stir in yogurt. Add crabmeat, celery, and mustard; stir gently until combined. Taste crab filling and adjust seasoning, if necessary.
Arrange a fan of 3 lettuce leaves on each of 8 plates. Cut a thin slice from the bottom of each egg white half to help them sit flat. Pile the crab filling evenly into egg white halves. Place 2 egg white halves on each plate to one side of lettuce. Sprinkle reserved 1 tablespoon yolk over egg white halves. Arrange 1/4 cup radish mixture on the other side of each serving.