Brown meat in large skillet on medium-high heat; drain.
Add onions, garlic, oregano and crushed pepper; cook 5 min. of until onions are tender, stirring occasionally.
Spoon 1/4 cup meat mixture onto center of each tortilla; top with VELVEETA. Fold in all sides of tortillas to completely enclose filling; secure with wooden toothpicks.
Place in single layer on baking sheet. Refrigerate 20 min.
Heat oil in large saucepan on medium-high heat.
Add chimichangas, 2 at a time; cook 5 min. or until golden brown.
Drain on paper towels.
Remove and discard toothpicks.
Serve chimichangas topped with sour cream and cilantro.