Combine turkey, cilantro, garlic, pepper (and salt, if desired) in a large bowl. Mix until combined. Divide meat mixture into six separate ½-inch thick football-shaped patties.
Spray non-stick skillet with cooking spray.
Place patties in skillet over medium-high heat.
Cover and cook for 16-18 minutes, turning two to three times and until internal temperature reaches well-done, 165°F as measured by a meat thermometer.
Heat broiler.
Place turkey burger on garlic toast.
Top with chili and cheese.
Broil four to five inches from heat source for two to three minutes or until cheese is melted.
Top with sour cream.