In 10-inch nonstick skillet, heat oil over medium heat. Add onion and garlic; cook 2 to 3 minutes, stirring occasionally, until crisp-tender. Stir in chicken, jalapeño chiles, cumin and salsa verde; cook 4 to 6 minutes or until hot. Keep warm.
Heat tortillas as directed on package. Work with 4 tortillas at a time, covering remaining tortillas with a damp paper towel. Spoon 2 level tablespoons chicken mixture and 1 tablespoon shredded cheese in center of each tortilla. Top with tomato and cilantro. Fold 1/3 of tortilla down over filling; fold sides toward center. Fold remaining side up, and turn over. Repeat with remaining tortillas. Serve immediately.