In a medium mixing bowl, whisk together olive oil, fresh lemon juice, minced garlic, dried oregano, dried thyme, sea salt, black pepper, and red pepper flakes if using. Stir until well combined and the salt is dissolved. Pro tip: Make the marinade fresh while you're prepping the chicken—this ensures maximum flavor infusion and takes less than 5 minutes.

Pat the chicken breasts dry with paper towels, then cut them into uniform 1½-inch cubes. Even-sized pieces ensure the chicken cooks at the same rate for perfectly tender results. Pro tip: If your chicken breasts are particularly thick, pound them to an even thickness first, then cut into cubes.

Place the chicken cubes into a large zip-top bag or glass dish. Pour the marinade over the chicken, tossing to coat evenly. Remove as much air as possible from the bag and seal. Pro tip: For this grilled chicken skewers recipe, marinating for just 30 minutes yields great results, but overnight in the refrigerator develops even more complex flavor.

Refrigerate the marinating chicken for at least 30 minutes, or up to 12 hours. If marinating longer than 2 hours, remove from the refrigerator 15-20 minutes before grilling to bring the chicken closer to room temperature. Pro tip: I like to prepare this the night before entertaining—it saves so much time on the day of and allows flavors to deepen beautifully.

While the chicken marinates (or shortly before grilling), prepare your vegetables. Cut the red bell pepper and yellow onion into 1-inch chunks, and halve any large mushrooms. Toss the vegetables with a drizzle of olive oil and a squeeze of lemon juice, seasoning lightly with salt and pepper. Pro tip: Keep vegetables relatively uniform in size so they cook evenly alongside your chicken pieces.

If using wooden skewers, submerge them in water for 30 minutes to prevent burning on the grill. Thread the marinated chicken and vegetables alternately onto the skewers, starting and ending with chicken. Leave about ¼ inch between pieces for even heat circulation. Pro tip: Don't pack the skewers too tightly—this recipe works best when there's a little space between ingredients for heat to circulate and create those beautiful grill marks.

Preheat your grill to medium-high heat (about 400°F). Clean the grill grates with a brush and lightly oil them with a high-heat oil to prevent sticking. Pro tip: Let your grill preheat for at least 10-15 minutes to ensure even cooking and beautiful char marks on your easy grilled chicken kabobs.

Carefully place the loaded skewers on the preheated grill. For this grilled chicken skewers recipe, grill for 12-15 minutes total, turning every 3-4 minutes to ensure even cooking and prevent burning. You're looking for beautiful grill marks and an internal temperature of 165°F. Pro tip: The key to how to grill chicken skewers perfectly is patience and not moving them around too much initially. Let them sit for 3-4 minutes before the first flip to develop those gorgeous caramelized marks.

Use an instant-read meat thermometer to check doneness by inserting it into the thickest piece of chicken. Once it reaches 165°F, your skewers are ready to rest. Pro tip: Don't cut into the chicken to check for doneness—this releases precious juices. Always use a meat thermometer for accuracy.

Transfer the grilled chicken appetizers to a clean plate or serving platter and let them rest for 5 minutes before serving. This allows the juices to redistribute, ensuring every bite remains incredibly juicy. Pro tip: Tent loosely with foil during the resting period if your kitchen is particularly cool, keeping the skewers warm without steaming away their delicious char.

Serve your marinated chicken skewers immediately while they're hot, optionally garnished with fresh parsley, extra lemon wedges, and crumbled feta cheese if desired. Pro tip: For summer grilling recipes that really shine, present the skewers on a bed of fresh herbs or alongside a crisp, cold salad for the perfect contrast.