Prepare the Marinade: In a large bowl, whisk together the olive oil, lemon juice and zest, minced garlic, smoked paprika, dried oregano, salt, and black pepper until well combined.

Marinate the Chicken: Add the cubed chicken thighs to the bowl with the marinade. Toss everything together until each piece of chicken is thoroughly coated. Cover the bowl and let it marinate in the refrigerator for at least 30 minutes, but no longer than 4 hours (the lemon juice can start to affect the texture if left too long).

Prepare the Skewers: While the chicken is marinating, if you're using wooden skewers, submerge them in water. This stops them from burning to a crisp on the grill. If using metal skewers, you can skip this step.

Assemble the Skewers: Thread the marinated chicken onto the skewers, alternating with pieces of red pepper, yellow pepper, courgette, and red onion. Don't pack the pieces too tightly together; leaving a little space ensures everything cooks evenly.

Preheat the Grill: Preheat your outdoor grill or indoor grill pan to a medium-high heat, around 200°C (400°F). Lightly oil the grates to prevent sticking.

Grill the Skewers: Place the skewers on the preheated grill. Cook for about 10-15 minutes, turning them every 3-4 minutes, until the chicken is cooked through and the vegetables are tender with nice char marks. I find that using tongs gives you the most control for even cooking on all sides.

Check for Doneness: The safest way to check if the chicken is cooked is with a meat thermometer. It should read 74°C (165°F) at the thickest part. You can find more detailed guidance on cooking chicken safely from the Food Standards Agency.

Rest and Serve: Remove the skewers from the grill and let them rest on a platter for 5 minutes. This allows the juices to redistribute, ensuring the chicken is as succulent as possible. Serve warm.