Whisk together 1/4 cup olive oil, 2 minced garlic cloves, 1/2 cup chopped parsley, 2 tablespoons red wine vinegar, salt, and pepper in a shallow dish. Add the chicken breasts, turning to coat completely, and marinate for at least 30 minutes in the refrigerator or up to overnight for best flavor.

While the chicken marinates, prepare your chimichurri sauce by combining 3/4 cup parsley, 3 minced garlic cloves, red pepper flakes, remaining 2 tablespoons red wine vinegar, and 1/2 cup olive oil in a food processor. Pulse until you achieve a chunky sauce with visible herb pieces. It should look bright green and thick. Taste and adjust salt as needed.

Mix together the mayonnaise, sour cream or Greek yogurt, lemon juice, remaining 1 minced garlic clove, 1 tablespoon fresh chopped herbs, and a pinch of salt and pepper for the creamy garlic sauce. Refrigerate while you cook the chicken.

Preheat your grill or grill pan to medium-high heat (about 400 to 450°F). Remove chicken from marinade, letting excess drip off, and grill for 5 to 7 minutes per side until the internal temperature reaches 165°F on a meat thermometer and you see char marks. Let the chicken rest for 5 minutes before slicing.

Divide the fresh greens between serving bowls. Top with sliced grilled chicken, spoon diced tomatoes around the chicken, drizzle generously with chimichurri sauce, and finish with a dollop of the creamy garlic sauce.