01 -  Preheat oven to 350°F. 
 02 -  Boil ramen noodles for 2 minutes less than package directions; drain and set aside. 
 03 -  Heat vegetable oil in a large skillet over medium heat. Sauté onion, garlic, and ginger until fragrant and translucent, about 3 minutes. 
 04 -  Add ground pork and cook, breaking up the meat with a spoon, until evenly browned. 
 05 -  Stir in gochujang, red pepper flakes, crushed tomatoes, soy sauce, rice vinegar, and sugar. Season with salt and pepper. Simmer for 10 minutes until sauce thickens slightly. 
 06 -  Combine ricotta cheese, one egg, half the mozzarella, and half the parmesan in a bowl until smooth. 
 07 -  Spread a thin layer of meat sauce on the bottom of a 9x13-inch baking dish. 
 08 -  Arrange a layer of cooked ramen noodles (using roughly one pack per layer, fit to cover). Spread a third of the cheese mixture on top, then a third of the meat sauce. Repeat for two more layers, finishing with remaining meat sauce. 
 09 -  Sprinkle remaining mozzarella and parmesan evenly over the surface. 
 10 -  Cover with aluminum foil and bake for 20 minutes. 
 11 -  Remove foil and bake an additional 10 to 15 minutes until cheese is bubbling and lightly golden. 
 12 -  Allow lasagna to stand for 10 minutes before slicing. Garnish with green onions if desired.