Preheat oven to 350 degrees.
In a medium-sized mixing bowl, combine chicken, sour cream, salt, pepper, and garlic powder. Set aside.
In a separate small bowl, combine cheese and southwest seasoning. Set aside.
Spray 2 muffin pans with cooking spray.
Place one wonton wrapper in each muffin cup; bake 8-10 minutes, until lightly brown.
Remove from oven and cool.
Spoon chicken filling into each wonton cup, filling almost until full.
Sprinkle with cheese mixture and bell peppers. *Cups will be full.
Return to oven and bake for an additional 10 minutes, until wontons are golden brown and cheese is melted.