Heat a large heavy duty pan on high heat. Add the oil and allow to heat for at least 1 minute. Add the chicken and cook for 5 minutes. Remove chicken from the pan and set aside.
Add the garlic to the same pan and saute for 20 seconds. Add the Mushrooms, broccoli, and bell peppers. Stir for 2 minutes or until the broccoli is tender.
Add the soy sauce, ketchup, and sriracha. Stir for 2 minutes. Return the chicken back into the pan and stir-fry for about 2 minutes or until the broccoli is tender and everything is well combined.
Serve on rice, noodles, or in lettuce leaves.
For a thick sauce, mix in 2 tablespoons of cornstarch with the soy sauce before adding it to the pan. I prefer using chicken thighs because they stay moist but feel free to replace thighs with breasts or thinly sliced beef.