For the avocado puree with eggs and sprouts, rinse the hard-boiled eggs with cold water, peel and cut in half lengthwise. Cut the avocado in half, remove the pit, scoop out the flesh with a coffee spoon and cut into small pieces. Immediately puree with yogurt and lemon juice in a blender (to prevent flesh from turning brown).
Pass through a sieve and season with salt and pepper. Place washed, drained lettuce leaves on plates, top with the avocado puree and top each with 3 egg halves. Sprinkle with the sprouts.