Heat oven to 350. Lightly spray a 9" x 13" casserole dish w/ cooking spray. In a medium bowl, stir together the sour cream, green onions, cilantro, ( if using...I'm not, lol,) jalapeno pepper slices and cumin.
Spray a lg skillet w/ cooking spray. Pour in the oil and heat over med-high heat. Add chicken and garlic. saute until chicken is cooked, about 4 mins.
Divide the chicken strips among the flour tortillas, placing them down the center of each tortilla. Top w/ the sour cream mix, sprinkle w/ some of the cheese. Roll them up and place them, seam side down in the baking dish. Sprinkle w/ remaining cheese and cover w/ foil. Bake 30 mins, or until bubbly. Spoon the salsa down the middle, then sprinkle w/ chopped tomato. Garnish w/ cilantro, if you like. Serve w/ extra sour cream and black olives.