Chop your onion, mince your garlic, and slice your bell peppers.
Slice your chicken breasts by butterflying them first. To do that, place your hand on top of the chicken breast and slice horizontally straight into the middle until you can unfold the chicken breast and its width doubles, and then slice into thin pieces.
When the chicken is fully cooked, remove it to a bowl and place the pan back on the heat. Add 1 tbsp of oil and when it's heated, add the shrimp. While they're cooking, season the shrimp with the garlic powder and a pinch of pepper (if you wish). You'll know they're done when they turn pink (a few minutes). Transfer to the same bowl as the chicken.
Next, add the last tablespoon of your oil to the pan and add the onion and garlic. Cook for 2-3 minutes or until the onions soften slightly. Add the few tablespoons of white wine to the pan. It will start bubbling vigorously right away, so stir it around with the onions and garlic and let the wine soften the browned bits (leftover from the chicken and shrimp) stuck to the bottom of the pan. If you don't have any wine on hand, a few tablespoons of chicken broth will do the trick. Once you've deglazed the pan, add the rice, tomatoes (in their juice! Don't drain them!), chicken broth, and spices.