Marinate: In a bowl, toss the cubed chicken with 1 tablespoon of coconut aminos (or soy sauce), half of the minced garlic, and 0.5 teaspoon of cracked black pepper. Marinate at room temperature for 10 minutes.
Sear Chicken: Heat 1 tablespoon of extra virgin olive oil in a large skillet over medium-high heat. Add the chicken in a single layer. Cook for 5–6 minutes, turning occasionally, until golden-brown and cooked through. Transfer to a plate.
Cook Veggies: Add the remaining 1 tablespoon of olive oil to the same skillet. Add the sliced mushrooms and onions, cooking for 3 minutes until softened. Toss in the red and green bell peppers and the remaining garlic, cooking for 2 more minutes.
Make Sauce: Whisk together the remaining coconut aminos, oyster sauce, balsamic vinegar, chicken broth, and the remaining 1 teaspoon of cracked black pepper in a small bowl.
Combine & Finish: Return the cooked chicken to the skillet with the vegetables. Pour the sauce mixture over everything. Toss continuously over high heat for 1–2 minutes until the sauce bubbles, glazes the ingredients, and thickens slightly. Serve hot.