01 - Set oven to 350°F (180°C) to heat thoroughly.
02 - Boil ramen noodles for 2 minutes less than package instructions. Drain well and set aside.
03 - In a large skillet over medium heat, warm vegetable oil. Add chopped onion, minced garlic, and grated ginger. Sauté until translucent and aromatic, about 3 minutes.
04 - Add ground pork and cook, breaking apart with a spoon, until browned throughout.
05 - Stir in gochujang, crushed red pepper flakes, crushed tomatoes, soy sauce, rice vinegar, and sugar. Season with salt and pepper. Bring to a gentle simmer and cook for 10 minutes, allowing sauce to thicken slightly.
06 - Combine ricotta cheese, egg, half the shredded mozzarella, and half the parmesan in a mixing bowl. Blend well until smooth.
07 - In a 9x13-inch baking dish, spread a thin layer of meat sauce on the bottom.
08 - Arrange approximately one pack of par-boiled ramen noodles over the sauce, fitting as evenly as possible.
09 - Distribute one third of ricotta mixture over the noodles, then top with one third of remaining meat sauce. Repeat these layers twice more, finishing with remaining meat sauce.
10 - Sprinkle remaining mozzarella and parmesan evenly across the top. Cover dish with aluminum foil and bake for 20 minutes.
11 - Remove foil and continue baking for 10 to 15 minutes, until cheese is bubbling and lightly golden.
12 - Let lasagna cool for 10 minutes before slicing. Top with green onions if desired.