Heat large non-stick or stainless steel skillet over medium heat and add in butter to melt.
Whisk together eggs and add to melted butter. Scramble eggs in skillet until eggs are just set and remove from skillet.
Add in 1/2 tablespoon oil to the same skillet and turn to medium-high heat. Add in veggies and stir frequently for 3 minutes, or until veggies begin to soften.
Once vegetables have begun to soften, increase heat to high and add in remaining 1/2 tablespoon of oil, cold rice, soy sauce, and rice wine vinegar. Stir everything together to evenly distribute ingredients. Continue to stirring until rice has begun to brown and get crispy and is warmed through--3-5 minutes, depending on the size of your skillet.
Turn off heat and add in eggs, sesame seeds and oil (if using) and mix to combine. Serve with additional soy sauce and Sriracha on the side.
Be sure to use cold rice, leftover rice works best.
If you don't have avocado oil, peanut or vegetable oil will work.
Serve with additional soy sauce and Sriracha if desired.