Whisk eggs in a bowl. Heat a large skillet or wok with vegetable oil. Once oil is heated, add eggs to skillet. Scramble and break eggs into small pieces. Once eggs are fully cooked, removed and set aside.
Heat skillet on medium high/high heat. Add vegetable oil. Once oil is heated, add diced onions. Stir continuously until onions are soft and slightly translucent.
Add spam and garlic. Stir fry for ~1 minutes, but avoid burning garlic.
Add cooked rice to skillet, stir to combine. Break rice apart if they are in clumps. Cook for 1-2 minutes. Stir continuously.
Add mixed vegetables. Stir to combine.
Add scrambled eggs back into the skillet. Stir to combine.
Add butter and fold it into the spam fried rice while it melts.
Remove from heat. Serve and enjoy!