01 - Adjust oven rack to center position and preheat to 350°F (180°C).
02 - Boil ramen noodles in a large pot for 2 minutes less than package directions. Drain noodles and set aside.
03 - Heat vegetable oil in a large skillet over medium heat. Add chopped onion, minced garlic, and grated ginger. Sauté for about 3 minutes until the mixture is fragrant and translucent.
04 - Add ground pork to the skillet; cook, breaking apart with a spoon, until meat is browned throughout.
05 - Incorporate gochujang, crushed red pepper flakes, crushed tomatoes, soy sauce, rice vinegar, and sugar. Season with salt and freshly ground pepper. Stir and simmer for 10 minutes until sauce thickens slightly.
06 - In a mixing bowl, combine ricotta cheese, egg, half the mozzarella, and half the parmesan. Stir until the mixture is smooth.
07 - Spread a thin layer of meat sauce on the bottom of a 9x13-inch baking dish. Add a layer of cooked ramen noodles, arranging to cover the sauce. Spread one third of the ricotta mixture over the noodles, then top with one third of the meat sauce. Repeat the layering process two more times, ending with the remaining meat sauce.
08 - Sprinkle over the dish the reserved mozzarella and parmesan cheese.
09 - Cover the dish tightly with aluminum foil and bake for 20 minutes.
10 - Remove foil and continue baking for 10 to 15 minutes longer, until the cheese is golden and bubbling.
11 - Allow lasagna to rest for 10 minutes before slicing. Garnish with sliced green onions, if desired.