Peel and finely chop the onion. Heat 1 tablespoon of oil in a pot and fry the onion until transparent, turning it over. Add lentils, deglaze with 500 ml water, bring to the boil, cover and cook for 8-10 minutes. Then season with salt and pepper, pour into a sieve and drain well.
In the meantime peel oranges in such a way that the white skin is completely removed. Remove the fillets with a sharp knife between the parting skins. Squeeze the juice out of the parting skins. Cut the pomegranate in half and knock the seeds out with the back of a tablespoon.
Clean, wash and drain the salad. For the dressing, mix orange juice, grenadine syrup, vinegar, salt, pepper and sugar well. Fold in 4 tablespoons of oil.
Halve the avocado, remove the stone, remove the flesh from the skin and cut crosswise into slices. Mix lentils, lamb's lettuce, pomegranate seeds, oranges and avocado with the dressing, season with salt and pepper and serve.