HEAT 1 Tbsp. of the oil in large skillet on medium-high heat. Add onions and garlic; cook and stir 5 min. or until crisp-tender. Add meat, epazote and seasonings; mix well. Cover. Cook 8 to 10 min. or until heated through, stirring occasionally. Remove from heat; stir in sour cream.
BRUSH sopes evenly with remaining 2 Tbsp. oil. Cook on hot griddle for 2 min. on each side or until lightly browned on both sides.
TOP each sope with about 1/4 cup of the pork mixture. Serve immediately.