Heat a dry wok or large pan over medium-high heat. Fry the diced Spam until golden brown, then add the shallots and cook until softened.
Add the vegetable oil, green onions, and garlic, and stir-fry until fragrant, about 10 seconds. Then add the corn, peas, and carrots, and toss until evenly combined. Push everything to one side of the pan to create an empty space.
Pour the beaten eggs into the cleared space. Let them set for 10-15 seconds before scrambling, then break into bite-sized pieces.
Add the cold, day-old rice. Pour the regular soy sauce and dark soy sauce around the edges of the pan and let it sizzle for about 5 seconds. Add the unsalted butter, and season with salt if needed.
Toss everything until evenly combined and no white grains remain. Finish with sesame oil and garnish with extra green onions. Enjoy!
