In a mixing bowl, combine the minced garlic, mustard, honey, salt, pepper, chili flakes (if using), balsamic vinegar, and chicken stock. Whisk until well blended. Add the chicken breasts to the bowl, ensuring they are fully coated in the marinade. Cover and refrigerate for at least 30 minutes to allow the flavors to penetrate.
Heat a grill or stovetop skillet over medium-high heat. Remove the chicken from the marinade (reserving the marinade) and cook for about 6-7 minutes on each side, or until the chicken is cooked through and has nice grill marks. Let the chicken rest for a few minutes before slicing it into strips.
In a clean mixing bowl, combine the minced shallots, fresh rosemary, minced blackberries, honey, mustard, salt, balsamic vinegar, and olive oil. Whisk until emulsified. Set aside.
In a large salad bowl, combine the greens, sliced roasted beets, blackberries, avocado, red onion, and bocconcini. Top with the sliced chicken. Drizzle the salad with the prepared dressing and toss gently to combine, ensuring everything is evenly coated.
Serve the salad immediately while the chicken is still warm, or refrigerate for later. This salad is delicious on its own or paired with crusty bread for a complete meal.
