Take the chicken and cut into cubes. On a plate, put the flour, garlic powder, and pepper. Dredge the chicken in the mixture coating all pieces.
In the bottom of a large pan, I use a covered stock pot, heat about 1 tbs. of oil in the bottom of a pan. Add the chicken to the pan and cook until all the chicken is nice and crispy, around 10 minutes. Stiring occasially to make sure all parts are browned. Once the chicken has cooked take it out of the pan and set aside.
In the same pan add butter and let it melt. Add the sliced mushrooms and chopped onion. Cook until the mushrooms start to shrink and the onions are browned.
To the pan add the chicken back in. Now add the wet ingredients: chicken broth, fancy mixed vegetables (do not drain liquid), water chestnuts (do not dain liquid), and soy sauce. Finally to the pot add the rice and stir it all together.
Cover the pot and cook for 10 minutes. After 10 minutes check to see if you need to add any additional chicken stock so that the rice doesn't dry out. If there's still plenty of liquid allow to cook another 5-8 minutes covered.
Taste to make sure that the rice has cooked thoroughly and then add salt, pepper and more soy sauce to your taste. Enjoy!