Prepare the sauce by combining pineapple chunks, brown sugar, soy sauce, sriracha, garlic, and ginger in a bowl.
Heat vegetable oil in a large skillet over medium-high heat.
Add chicken breasts to the hot skillet and cook for about 6-7 minutes on each side, until browned and cooked through.
Remove the cooked chicken from the skillet and set aside.
In the same skillet, add the sauce mixture and bring to a simmer, scraping up any brown bits from the bottom.
Return the chicken to the skillet, spooning the sauce over to coat well.
Cook for an additional 3-4 minutes until the sauce thickens and clings to the chicken.
Serve hot, garnished with chopped green onions.
