Heat a large skillet or wok over medium-high heat and add the vegetable oil.
Once the oil is hot, add the chopped onion and minced garlic. Sauté for about 2 minutes until fragrant and the onion becomes translucent.
Push the onions and garlic to the side of the skillet. In the empty side, add the ground chicken. Cook for about 5-7 minutes, stirring occasionally until browned and fully cooked. Season with a pinch of salt and pepper.
Stir in the mixed vegetables and cook for another 3-4 minutes until they are heated through.
Move the chicken and vegetables to one side of the skillet, and pour the beaten eggs onto the other side. Scramble the eggs until fully cooked, then mix them into the chicken and vegetable mixture.
Add the cooked jasmine rice to the skillet, breaking up any clumps with a spatula. Stir to combine all the ingredients evenly.
Pour the soy sauce and sesame oil over the rice mixture. Toss everything together until well coated. Taste and adjust seasonings if necessary.
Finish off by mixing in sliced green onions. Let it all cook together for an additional 2-3 minutes, allowing the flavors to meld.
If desired, drizzle with sriracha or chili sauce for a touch of heat before serving.