Cook rice and let cool completely in the fridge for several hours or overnight.
In a large skillet, scramble 2 eggs and set aside.
In the same skillet, melt 2 tbsp butter and add frozen peas and carrots. Cook about 3 minutes.
Add diced onion, garlic, salt and pepper. Cook 2 minutes.
Add in cooked rice and 2 tbsp butter. Mix until combined.
Add 3 tbsp soy sauce and sesame oil (optional). Mix.
Add in the scrambled egg and other garnishes, such as chopped green onion.