For the marinade, mix the oil with the spices, tomato paste, a little lemon juice and the finely chopped garlic.
Cut the cauliflower and stem into small pieces and add to the marinade. Stir the pieces well so that everything is moistened with the marinade. Set the cauliflower aside and let it steep for about 20-30 minutes.
Wash the lentils and bring to the boil with about twice the amount of water, add the vegetable stock. Let the lentils simmer for 15-20 minutes.
Meanwhile, cut the avocado into cubes and mix with the garlic, lemon juice and olive oil, then season with salt and pepper.
Season the yoghurt with garlic, lemon juice, Ras el Hanout and Garam masala to taste. (If you want it to go faster, you can also add the avocado directly to the yogurt.)
Then fry the cauliflower in a pan for about 10 minutes, it should still have a bite. Let the lentils simmer for a few more minutes at the same time, until they are cooked but not mushy, then drain.