Dice the chicken thighs into bite-sized chunks, looking for pieces that are uniform in size for even cooking. Place them in a large mixing bowl.
In a small bowl, whisk together olive oil, lemon juice, oregano, garlic powder, paprika, salt, and pepper to create the marinade. Pour it over the chicken and toss to coat thoroughly. Cover and refrigerate for at least 2 hours, or overnight for deeper flavor.
Preheat your grill to medium-high heat until you hear a steady sizzle. Meanwhile, prepare the vegetables by cutting bell peppers into chunks and red onion into similar-sized pieces.
If using wooden skewers, soak them in water for at least 30 minutes to prevent burning. Thread the marinated chicken pieces, bell peppers, and onion chunks alternately onto skewers, creating colorful, balanced skewers.
Place the skewers on the hot grill, positioning them over the grates. Cook for about 6–8 minutes per side, turning occasionally, until the chicken is golden brown and cooked through, with juices running clear.
Use tongs to remove the skewers from the grill once the chicken reaches 165°F internally and has a nice smoky char. Let them rest for a couple of minutes to allow juices to settle.
Serve the skewers hot, with the vegetables slightly caramelized and tender, and the chicken juicy and flavorful. Enjoy the smoky, colorful bites straight from the grill!
