Roasted Green Chile Burgers with Grilled Sweet Onions and Salsa Mayo

Name: Roasted Green Chile Burgers with Grilled Sweet Onions and Salsa Mayo
Prep time: 15 min
Cook time: 20 min
Total time: 35 min
Cuisine: American, TexMex
Ingredients: 2-3 whole chile peppers; 1 1/4 pounds ground chuck (, 80/20 ratio of lean meat to fat); 3/4 cup cubed or shredded cheddar cheese (, or Jack cheese(1/4" cubes)); 1 teaspoon granulated onion; 1 teaspoon smoked paprika; 3/4 teaspoon sea salt; 1/2 teaspoon garlic powder; 1/2 teaspoon pepper; 4 Sprouted Wheat Burger Buns; 1/4 cup mayonnaise; 1/2 cup salsa (, any favorite, drained); 2 large sweet onions (, like Vidalia or Maui, sliced 1/4" thick); 2 tablespoons extra virgin olive oil; Sea salt and freshly ground pepper