Whisk together olive oil, lemon juice and zest, garlic, oregano, paprika, salt, and pepper. Stir in yogurt if using.
Add chicken pieces to a large bowl or zip-top bag. Pour marinade over and toss to coat. Cover and marinate in the fridge for at least 1 hour—longer is even better.
Heat your BBQ to medium-high and lightly oil the grates.
Thread the marinated chicken onto skewers. Leave a little space between pieces so they cook evenly.
Place skewers on the grill and cook for 12–15 minutes, turning occasionally, until the chicken is fully cooked and has nice charred edges.
Let rest a few minutes, then serve warm with your favourite sides!