Place 2 tablespoons olive oil in frying pan with the onion, garlic, green pepper, jalapeno pepper, and mushrooms. Cook 1 minute. Do not let garlic brown. Add 1/2 jar taco sauce. Cook about 1 minute. Add shredded chicken; toss to coat. Add Monterey Jack cheese; cover and simmer 5-10 minutes until chicken is hot and cheese is melted.
Place 1 tablespoon olive oil in a skillet. Heat on medium until very warm. Place flour tortillas in pan and warm both sides. Place tortilla on a plate and fill one side with chicken-cheese mixture. Fold over to cover mixture. Top with salsa, about 1 1/2 tablespoons sour cream and a few black olive slices. Serve with lettuce and tomatoes, refried beans, or rice and beans.
