Put the yogurt in a small bowl with the cucumber, lemon juice, garlic and a pinch of salt and pepper.
Stir together and pop in the fridge to allow the flavours to develop while you make the rest of the dish. You can season further before serving, if required.
Make the couscous
Put the couscous in a large, heatproof bowl. Crumble the stock cube on top.
Add 210ml of boiling water. Stir well, then cover with a plate and set aside.
Meanwhile, heat the oil in a large pan over a medium heat.
Add the spices and a pinch of salt and pepper and fry for 30-60 seconds until fragrant.
Add the mixed veg and garlic fry for 3-4 minutes until cooked through.
Fork through the couscous then add the vegetables and stir together. Cover again.
Cook the halloumi
Heat a griddle pan (or standard frying pan) and lightly oil.
Fry the halloumi slices for just a minute or two on each side to give golden griddle marks and a gooey soft halloumi.
Serve
Serve the couscous into bowls.
Top with a couple of halloumi slices.
Dress with the tzatziki dressing and few slices of fresh chilli. Serve any leftover dressing to the table so that people can help themselves.