12 (5 inches long) poblano chiles
2 cups (12 ounces) crumbled feta cheese
2 cups (8 ounces) shredded white Cheddar cheese
2 cups (8 ounces) shredded Monterey Jack cheese
8 ounces cream cheese
1 tablespoon fresh lime juice
4 green onions, thinly sliced
1 tablespoon pepper
Vegetable oil, as needed
8 eggs, separated
1 1/2 cups all-purpose flour
Roast the whole chiles over an open flame, turning frequently, until blackened and blistered all over. Put the roasted chiles into an ice-water bath to cool; peel off the skin under running water. Cut a slit in the side of each chile to make a pocket. Set aside.
Mix the cheeses, lime juice, green onions, and pepper together until well-blended. Carefully stuff each chile with about 1/4 cup of the cheese mixture. Set aside.
In a 10-inch skillet, heat 3/4 inch of oil to 325°F. While the oil is heating, beat the egg whites until stiff. Add the yolks and mix just until blended, 5 to 10 seconds more. Roll the stuffed chiles in flour, coating the entire chile. Coat the chiles with the egg mixture and fry, 3 to 4 at a time, until both sides are golden brown. Remove onto paper towels. Repeat the process until all of the chiles are fried. Chiles can be reheated in the microwave for 1 to 2 minutes before serving with your favorite salsa.