Preheat oven to 375°. In a small skillet, cook chorizo over medium heat until cooked through, breaking into crumbles, 5-7 minutes; drain. Transfer to a large bowl. Stir in the hash browns, soup, cheeses, onion, peppers and pepper flakes. Transfer to a greased 13x9-in. baking dish. Sprinkle with panko.
Bake, uncovered, until golden brown and bubbly, 40-45 minutes. Sprinkle with parsley and cilantro before serving.
