Fajita Burger with Guacamole

Name: Fajita Burger with Guacamole
Ingredients: 3 tablespoons sour cream; 2 ripe avocados; 1 tablespoon lime juice; Several dashes hot sauce; 2 tablespoons Worcestershire sauce; Kosher salt and freshly ground black pepper; 1/2 cup fresh cilantro leaves, chopped; 2 tablespoons vegetable oil, plus more for the grill grates; 2 bell peppers (any color is fine), thinly sliced; 1 onion, halved and thinly sliced; 1 jalapeno, seeded and thinly sliced; 1 tablespoon plus 1 teaspoon chile powder; 1 1/2 pounds ground beef chuck (80/20); Four 1-ounce slices pepper jack cheese; 4 hamburger buns, split