Place lentils into boiling water, bring to a boil and cook for about 8-10 minutes on low heat. Drain and rinse in cold water, drain well.
Rinse and dry scallions, cut dark green parts into rings. Rinse and trim snow peas, halve diagonally. Blanch scallions and snow peas in boiling salted water for 2 minutes. Drain and rinse in cold water, drain well.
Rinse and trim radishes, cut into slices.
Whisk vinegar with oil and season with salt and pepper. Combine lentils, radishes and snow peas, toss with the dressing and let stand for 20 minutes.
Halve avocado and remove pulp with a spoon. Slice and sprinkle immediately with lemon juice.
Rinse sprouts in hot water, drain well.
Season salad to taste and garnish with scallions, avocado and sprouts. Serve.