Soak lentils overnight. Drain the next day and cook in plenty of salted water for about 1 hour. Drain well. Rinse tomatoes and quarter.
Rinse radishes and cut into small sticks. Rinse, peel and cut carrots into small cubes. Rinse scallions and cut into rings. Peel onion and dice finely. Peel cucumber, halve lengthwise, scrape out seeds and dice finely.
3. Prepare salad.
Combine lentils and all vegetables, mix well. Add parsley. Combine safflower oil and vinegar, season with salt and pepper. Drizzle dressing over lentil salad and mix well. Arrange salad on lettuce leaves and purslane, serve.