In a small saucepan over low heat, combine the cornstarch, cold water, sugar, soy sauce, vinegar, garlic, ginger and ground black pepper. Let simmer, stirring frequently, until sauce thickens and bubbles. Remove from heat.
Lay chicken breasts into glass baking dish. Pour teriyaki sauce over each piece. Using tongs, turn pieces thoroughly to coat with the sauce, then cover with aluminum foil and place in oven.
Bake at 425 degrees for 20 minutes. Remove pan from oven, uncover, turn chicken pieces with tongs, then return to oven and continue cooking (uncovered) for another 10 minutes. Serve with simple cauliflower fried rice.
Cut the cauliflower into florets, discarding the tough inner core. Working in batches, pulse the cauliflower in a food processor until it breaks down into rice-sized pieces.
In a small side skillet, add a little butter. When bubbling, add in your eggs. As eggs begin to white, use a wooden spatula to ‘scramble in place’. Turn off heat - set aside.
Heat a large skillet and melt 1 tbsp. coconut oil to coat bottom of the pan. Add the ginger and garlic, and sauté until fragrant, about 30 seconds.
Stir in the carrots and sauté until crisp-tender, 2 minutes. Stir the cauliflower "rice" and peas into the pan, mixing the ingredients thoroughly.
Lower the heat to medium, cover the pan, and cook until the cauliflower is tender, 3-5 minutes.
Uncover and stir in the eggs, green onions, and 2 tablespoons of soy sauce. Add more soy sauce to taste. Serve immediately with the teriyaki chicken.