Description:

Ingredients for 4 portions:
(exact measurements are not critical, as you can stuff these with anything that fits)

For the filling:
1 tbsp vegetable oil, divided (half for veggies, half to cook chicken)
1/2 cup diced onions
1/2 cup diced poblano peppers
1/2 cup sliced mushrooms
12 oz boneless skinless chicken breast meat, cut in 1/2-inch cubes
salt, freshly ground black pepper, cayenne pepper to taste
1/4 tsp cumin
1/4 tsp chipotle, smoked paprika, or other hot or mild ground chili pepper
pinch dried Mexican oregano
1 or 2 tbsp cold water to deglaze pan once chicken is browned
4 ounces grated pepper Jack cheese

Also:
4 large flour tortilla (at least 10-inch wide)
1 egg white
2 tbsp vegetable oil for pan-frying
sour cream, guacamole, and salsa to garnish, optional