I don’t have a have a tagine dish, but it works equally well in my trusty Le Creuset casserole, you’d never know the difference.
I browned the lamb in goose fat, added some red onions, chilli and garlic and cooked it for a bit, then I added a teaspoon of sumac (optional) and garam masala and one and a half of harissa paste, a couple of pieces of lime and cooked it all for a bit more..
I added about a dessert spoon of tomato juice which was in the fridge from something else, and good glug of bordeaux, but only because it was there and some water, popped it in the oven on very low (about 100) and left it for 4 hours.
Then I added chopped dates, a couple of cherry tomatoes, peppers and chickpeas.
put it back in the oven, turned the heat up a bit and left it for another hour.
I served it with cous cous, pitta bread and some pomegranate and a red onion salady thing..