In a bowl, whisk together olive oil, lime juice, minced garlic, oregano, cumin, salt, and pepper for the chicken marinade. Add chicken thighs and toss to coat. Marinate for at least 15 minutes, or up to 4 hours in the refrigerator.
While the chicken marinates, prepare the chimichurri sauce. In a small bowl, combine chopped parsley, cilantro, red wine vinegar, olive oil, minced garlic, red pepper flakes, salt, and pepper. Stir well and set aside.
Heat a grill pan or outdoor grill to medium-high heat. Cook the marinated chicken thighs for 6-8 minutes per side, or until cooked through and nicely charred. Let rest for a few minutes before slicing.
Assemble the bowls. Divide the cooked quinoa or rice among four bowls. Top with sliced chicken, black beans, corn, cherry tomatoes, and sliced avocado.
Drizzle generously with the prepared chimichurri sauce and serve immediately.
Notes
This recipe can be customized with your favorite vegetables. For a spicier kick, add an extra pinch of red pepper flakes to the chimichurri.