Make the marinade. In a large bowl (or zip-top bag), whisk together 1 cup Greek yogurt, olive oil, lemon zest, lemon juice, garlic, salt, cumin, smoked paprika, and black pepper.
Marinate the chicken. Add chicken pieces and toss until every piece is well coated. Cover and refrigerate at least 30 minutes, or up to 8 hours.
Pro move: Before cooking, let excess marinade drip off the chicken (do not wipe it clean, just do not let it go on in thick globs). Yogurt can darken fast over high heat, so this keeps the char in the fun zone.
Prep skewers and veggies. If using wooden skewers, soak them in water for 30 minutes. You will need about 6 to 8 skewers depending on size (or use two skewers per kebab if you want easier turning).
If using onion and pepper, toss them with a teaspoon of olive oil and a pinch of salt before skewering. You can also toss them in a spoonful of the leftover marinade, but keep it light so it does not scorch. Thread chicken onto skewers, leaving a little space between pieces for browning. Alternate chicken and veggies if you want mixed skewers.
Note: Veggies can cook a touch slower than chicken. If you like them softer, cut them slightly smaller than the chicken.
Cook on a grill (best option). Heat grill to medium-high and oil the grates. Grill kebabs 10 to 12 minutes total, turning every few minutes, until browned and the thickest piece hits 165°F.
No thermometer? Look for chicken that is no longer pink in the center and the juices run clear, with a nice browned exterior.
Or broil (awesome backup plan). Set oven rack about 6 inches from the broiler. Line a sheet pan with foil and lightly oil it. Arrange kebabs in a single layer. Broil 10 to 12 minutes, turning once halfway, until browned and cooked through (165°F).
No thermometer? Same idea: no pink in the center, juices run clear, edges browned.
Or use a grill pan (weeknight hero option). Heat a lightly oiled grill pan over medium-high until hot. Cook kebabs about 10 to 12 minutes total, turning every 2 to 3 minutes, until well browned and cooked through (165°F). Work in batches so you do not steam the chicken.
Mix the quick sauce. Stir together 1/2 cup yogurt, lemon juice, herbs, and a pinch of salt. Taste and adjust. More lemon if you want it brighter, more salt if it tastes sleepy (or flat).
Rest and serve. Let kebabs rest 3 minutes, then serve with the yogurt sauce. I love these with rice, warm pita, or roasted potatoes and a quick cucumber salad.
