Place the chicken breasts on the bottom of the Slow Cooker. Pour the chicken stock on top. Add mustard seeds and garlic powder. Set the timer to 6 hours and the temperature to “high”. Turn the breasts over about 2 times throughout the cooking, doing it for the first time 3 hours into the cooking process.
About 20 minutes before the chicken is ready, sauté the onions in a skillet with 1 to 2 tablespoons of oil, until slightly golden.
Add strips of bell pepper and sautee some more until the pepper has taken on some color and became tender.
Once the chicken is ready, shred it with two forks. Do not remove the leftover liquid, it will help to keep chicken moist.
Add sautéed onion & pepper & the sauce of your choice (Garlic Sweet Sauce/Teriyaki Sauce). Season with freshly ground black pepper, sriracha & salt to taste.