Follow these step-by-step instructions to achieve a perfectly grilled, juicy chicken and tender, flavorful vegetables every time. The process is broken down into marinating, prepping, and grilling for ultimate clarity.

Step 1: Prepare the Chicken and Marinade

First, prepare the chicken. If the chicken breasts are very thick, it’s a good idea to pound them to an even thickness (about 3/4 inch). This is a crucial step for even cooking. You can do this by placing the chicken between two sheets of plastic wrap and using a meat mallet or a heavy rolling pin. In a large bowl or a resealable plastic bag, whisk together all the ingredients for the marinade: the 1/2 cup of olive oil, fresh lemon juice, minced garlic, dried oregano, dried thyme, paprika, 1 1/2 teaspoons of sea salt, and 1 teaspoon of black pepper. Add the chicken breasts to the marinade and turn to coat them thoroughly. Ensure every piece is generously covered. Cover the bowl or seal the bag and place it in the refrigerator to marinate for at least 30 minutes. For the best, most deeply infused flavor, allow it to marinate for 2 to 4 hours. Do not marinate for more than 8 hours, as the lemon juice can start to break down the chicken’s texture too much.

Step 2: Prepare the Vegetables

While the chicken is marinating, you can prepare your vegetables. Wash and dry all the vegetables thoroughly. Cut the bell peppers into large, flat pieces or wide strips. Cut the red onion into thick, 1/2-inch rounds to prevent them from falling through the grill grates. Slice the zucchini and yellow squash lengthwise into long, 1/4-inch thick planks. This shape is ideal for grilling as it provides maximum surface area for charring and makes them easy to flip. Place all the prepared vegetables in a large bowl. Drizzle them with the 3 tablespoons of olive oil and season generously with salt and pepper. Toss gently with your hands or a large spoon until every piece is lightly coated.

Step 3: Preheat and Clean the Grill

About 15 minutes before you’re ready to cook, preheat your outdoor grill to a consistent medium-high heat, aiming for a temperature around 400-450°F (200-230°C). A properly heated grill is essential for getting those beautiful sear marks and preventing food from sticking. Once hot, use a stiff wire grill brush to thoroughly clean the grates. This removes any old, burnt-on food particles that could cause your chicken and veggies to stick or impart off-flavors. After brushing, you can lightly oil the grates by soaking a paper towel in a high-smoke-point oil (like canola or vegetable oil) and, holding it with long-handled tongs, rubbing it over the hot grates.

Step 4: Grill the Chicken

Remove the chicken from the marinade, allowing any excess to drip off; you don’t need to wipe it dry. Place the chicken breasts directly on the preheated, oiled grill grates. Grill for about 6-8 minutes on the first side. You’ll know it’s ready to flip when it releases easily from the grates. If it sticks, give it another 30-60 seconds. Flip the chicken and continue to grill for another 6-8 minutes on the other side. The total cooking time will depend on the thickness of your chicken. The most reliable way to check for doneness is with an instant-read meat thermometer. The chicken is fully cooked and safe to eat when the internal temperature in the thickest part reaches 165°F (74°C).

Step 5: Grill the Vegetables

You can grill the vegetables alongside the chicken or while the chicken is resting. Arrange the vegetable pieces on the grill in a single layer, ensuring they are not overcrowded. Overcrowding will cause the vegetables to steam rather than grill, and you won’t achieve that desirable char. Grill the vegetables for about 4-6 minutes per side. You are looking for them to be tender-crisp (cooked through but still with a slight bite) and have distinct grill marks. The bell peppers and onions might take a minute or two longer than the zucchini and squash. Use tongs to flip them carefully.

Step 6: Rest and Assemble the Platter

Once the chicken is cooked through, transfer it from the grill to a clean cutting board. Let it rest for at least 5-10 minutes. This is a non-negotiable step! Resting allows the juices to redistribute throughout the meat, ensuring every bite is moist and succulent. If you cut into it immediately, all the delicious juices will run out onto the board. While the chicken rests, remove the finished vegetables from the grill. To assemble, slice the rested chicken breasts against the grain into thick strips. Arrange the sliced chicken artfully on a large platter or wooden board. Surround the chicken with the colorful grilled vegetables, creating a beautiful and inviting presentation. Garnish with fresh parsley or a squeeze of fresh lemon juice if desired.