Remove the chicken breasts from the refrigerator and pat them completely dry using paper towels. This step is important because removing excess moisture helps the chicken develop a beautiful golden crust while grilling instead of steaming. If the chicken breasts are very thick, carefully slice them horizontally into thinner cutlets or gently pound them to an even thickness so they cook evenly and stay juicy.

Add the fresh parsley, cilantro, garlic cloves, olive oil, lemon juice, red wine vinegar, dried oregano, sea salt, black pepper, optional red pepper flakes, and optional turmeric to a blender or food processor. Blend the mixture in short pulses until everything is finely chopped and well combined but still slightly textured. Traditional chimichurri should not be completely smooth like a puree — leaving a little texture gives the sauce a fresher, more vibrant flavor.

Taste the chimichurri sauce and adjust the seasoning if needed. Add extra lemon juice for brightness, a little more olive oil for richness, or additional salt to enhance the flavor. If you enjoy extra heat, stir in more red pepper flakes gradually until it reaches your preferred spice level.

Reserve a portion of the chimichurri sauce in a separate bowl for serving later. This keeps some of the sauce fresh and vibrant for spooning over the grilled chicken after cooking. Coat the chicken thoroughly with the remaining chimichurri marinade, making sure all sides are evenly covered with the herbs, garlic, and oil mixture.

Cover the bowl tightly with plastic wrap or transfer the chicken into an airtight container or zip-top bag. Refrigerate for at least 30 minutes so the flavors can absorb into the chicken. For even deeper flavor and more tender meat, marinate for up to 8 hours. Avoid marinating much longer than that because the acidity from the lemon juice and vinegar can begin affecting the texture too much.

About 15–20 minutes before grilling, remove the chicken from the refrigerator so it can come slightly closer to room temperature. This helps the chicken cook more evenly. Preheat a grill or grill pan over medium heat until fully hot. If using an outdoor grill, lightly oil the grates to help prevent sticking.

Place the chicken onto the hot grill in a single layer, leaving some space between each piece. Avoid overcrowding the grill because too much chicken at once lowers the heat and prevents proper browning. Cook the chicken for about 5–7 minutes on the first side without moving it too much so it develops deep golden grill marks and flavorful caramelization.

Flip the chicken carefully using tongs and cook the second side for another 5–7 minutes, depending on thickness, until the chicken is fully cooked and beautifully golden brown. The internal temperature should reach 165°F in the thickest part. If the outside starts browning too quickly before the inside finishes cooking, slightly lower the heat to prevent drying out the meat.

Transfer the grilled chicken to a clean plate or cutting board and let it rest for 5–10 minutes before slicing. Resting allows the juices to redistribute throughout the meat, keeping the chicken tender, juicy, and flavorful instead of dry.

Slice the chicken against the grain for the most tender texture and arrange it on a serving plate. Spoon the reserved fresh chimichurri generously over the warm chicken just before serving. Garnish with extra parsley, cilantro, or lemon wedges if desired, and serve alongside roasted vegetables, salads, cauliflower rice, or Mediterranean-inspired side dishes for a fresh and satisfying meal.