In a medium bowl, combine water, kosher salt, sugar, and soy sauce. Stir until dissolved. Add chicken breasts and marinate for 15 minutes to 12 hours. Preheat oven to 425ºF.

In a saucepan over medium-high heat, combine chicken broth and minced garlic. Bring to a boil, then reduce to simmer for 5 minutes. Add 1 tablespoon of butter at a time until melted, then stir in pepper, thyme, and red pepper flakes. Remove from heat.

Remove chicken from the brine, pat dry, and sprinkle the mixed spices (onion powder, thyme, garlic powder) over the chicken. Place chicken in a baking dish. Pour the garlic sauce around the chicken and add whole garlic cloves.

Bake uncovered for 19-25 minutes or until chicken reaches 165°F. Broil briefly to melt cheese on top. Serve warm, garnished with chopped parsley.