Prepare the marinade: In a large mixing bowl, whisk together the yoghurt, olive oil, grated garlic, tomato purée, cumin, smoked paprika, ground coriander, black pepper, salt, and lemon juice. The mixture should be a pale rust colour, thick enough to coat the back of a spoon, and smell warmly aromatic with the spices. Add the beef cubes and toss until every piece is thoroughly coated. Cover the bowl with cling film and refrigerate for at least 2 hours, or up to 8 hours for deeper flavour.

Soak your skewers: If you are using wooden skewers, place them in a shallow dish of cold water and let them soak for 30 minutes. This prevents them from catching fire on the grill. Metal skewers need no preparation, but they do conduct heat, so handle them carefully when turning.

Assemble the kebabs: Remove the marinated beef from the fridge about 20 minutes before grilling to take the chill off. Thread the ingredients onto each skewer in a repeating pattern: a cube of beef, a square of red pepper, a wedge of onion, a courgette round, and a square of yellow pepper. Press each piece snugly against the next, but do not cram them together so tightly that the meat cannot cook evenly. Aim for 4-5 pieces of beef per skewer, depending on the length.

Preheat your grill: Whether using a charcoal grill, gas barbecue, or a cast-iron griddle pan indoors, get it hot. For a gas grill, set the burners to medium-high and close the lid for 10 minutes; the internal temperature should reach about 200°C. For a griddle pan, heat it over a high flame until a droplet of water sizzles and evaporates instantly. The surface must be properly hot to achieve those desirable char marks without stewing the meat.

Grill the kebabs: Place the assembled skewers on the hot grill, leaving a small gap between each one so the heat can circulate. Cook for 4 minutes without moving them — you should hear a satisfying sizzle as the meat hits the surface. After 4 minutes, use tongs to turn each skewer; the underside should show dark brown grill lines and the edges of the vegetables should be starting to soften. Continue grilling, turning every 3-4 minutes, for a total of 12-15 minutes. The beef should feel firm but with a slight spring when pressed, and the vegetables should be tender with lightly charred edges. If you prefer your beef medium-rare, aim for an internal temperature of 52°C; for medium, 58°C.

Rest and garnish: Transfer the cooked kebabs to a serving platter and tent loosely with foil. Let them rest for 5 minutes — this allows the juices to redistribute throughout the beef, ensuring every bite is moist rather than running onto the plate. Just before serving, sprinkle generously with the chopped parsley or mint and add a final squeeze of fresh lemon juice for brightness.