This Halloumi Burger features a massive punch of North African flavours and a healthy kick of chilli from harissa paste that helps make the most incredible onions.
Cut the halloumi cheese into slices that are good to fit on a bun. If you are getting "decent" stuff from a supermarket, the best way to do this is to pull along the fold line and then slide in a knife and cut to get a clean break.
Pour the olive oil and lemon over these slices, and then sprinkle over the sumac. Transfer them to the fridge and allow them to sit whilst we make the onions.
Peel and cut the onions into 7-10mm (¼-½") thick half-moon shapes.
Heat the oil for the onions over a medium-high heat in a 28cm or 11" frying pan (not nonstick).
Drop the onions into a pan with the oil and allow to cook for 10 mins.
Add in the Harissa paste and a pinch of salt, stir to combine, then reduce the heat to low-medium and then cook for a further 50 mins, stirring occasionally.
When the onions are almost done, slice your tomatoes into thick 1cm (½") slices.
Chop the lettuce and refresh it in iced water, then dry the lettuce and set it aside.
Heat a 30cm or 12" nonstick frying pan over a very high heat and sear the tomatoes on both sides for 60 seconds, and remove.
Add the marinated halloumi to the pan over a high heat and cook for two minutes on each side.
Add the sliced burger buns to the pan for the final 60 seconds.
Finally, build the burger. On with the lettuce, then tomato slices with a pinch of sea salt and zaatar, followed by the halloumi sprinkled with more zaatar. Then pile on the onions.