Preheat oven at 350 degrees Fahrenheit. In a medium-sized baking pan, place about 1 cup of the nacho chips at the bottom, lying them flat to form a bed of nacho chips. Place about 1/2 cup of the kimchi and 1/3 cup of the grated cheese evenly on top. Place the other 1 cup of nacho chips on top of the kimchi and cheese layer, forming another bed of nacho chips. Place the other 1/2 cup of kimchi and the other 2/3 cup cheese on top. Bake in the oven for about 5 minutes, or until the cheese is fully melted.
To make the spicy sauce, combine gochujang, Japanese mayonnaise, and sesame oil in a bowl. Set aside.
To make sunny side up eggs, heat 1 tsp of oil on a frying pan over medium high heat. Cook the egg for about 3-5 minutes, or until the egg whites are firm and cooked and the egg yolks are slightly runny.
To assemble dish, place the sunny side up egg in the middle of the nacho dish. Drizzle with sour cream and the spicy sauce. Top with green onions.