Peel and finely chop the shallots. Peel and crush the garlic. Warm the oil in a pan, add the shallots and garlic then cook over a moderate heat, stirring occasionally.
Chop the parsley, then stir into the shallots with the thyme leaves and sumac. Remove from the heat, add the lamb and season. You may find it easiest to use your hands. Roll into 12 small balls then flatten the top. Refrigerate for an hour
Make the sauce. Peel the onions, roughly chop and cook them in the oil over a moderate heat until translucent. Stir in the coriander, turmeric and a little salt and cook for 2 minutes, until the onions are pale gold.
Cut the broccoli into short lengths, then add to the onions with 100ml of boiling water. Cover and cook for 4 or 5 minutes until the broccoli is bright green.
Meanwhile fry the meatballs in a little oil over a high heat until golden brown and lightly pink in the middle.
Stir the crème fraîche into the broccoli, and warm thoroughly before spooning on to plates and adding meatballs. Scatter over a little finely ground sumac if you wish.