Put the basil, chilli, garlic, half the dill and 1 tbsp sunflower oil in a food processor and whizz until coarse. Cut halloumi in half down the natural seam and slice into fingers. Thread each piece onto a small skewer. Brush about half the herb mixture over the skewers.
Heat the remaining oil in a large frying pan, add roughly chopped onion and peppers and cook for 5 minutes over a medium heat until softened. Add tomatoes and rice, stir then pour in the hot stock. Bring to a boil, stir, reduce the heat to a gentle simmer, cover and cook for 10 minutes. Turn off the heat and leave for 5 minutes. Drizzle over the lemon juice and stir.
Meanwhile, heat a griddle pan over a medium-high heat, add the halloumi skewers and cook for about 5 minutes, turning once each side has char lines. Brush the remaining herb mixture over the hot halloumi.
Mix together the remaining onion, dill, capers, yoghurt and olive oil. Serve the rice and halloumi skewers with the caper yoghurt.