1. In a large skillet over medium-high heat, warm canola oil. Add ground pork, red onion, garlic, and red pepper flakes. Cook, breaking up the pork with a spoon, until the meat is browned and cooked through, 6 to 8 minutes. Stir in hoisin, then season with salt and pepper. Top with crushed peanuts and chopped scallions, then serve spooned into large individual lettuce leaves.