Preheat oven to 425°F (220°C). Toss peeled, diced sweet potatoes with olive oil, half the salt, and pepper. Spread on baking sheet and roast 25–30 minutes, stirring halfway, until golden and tender.
Pat chicken dry and season both sides with remaining salt and pepper.
Heat olive oil in a skillet over medium-high heat. Cook chicken 4–6 minutes per side until browned and cooked through. Remove and rest on plate.
In the same skillet, combine maple syrup, Dijon mustard, soy sauce, chicken broth, and minced garlic. Stir, scraping browned bits, and simmer 1–2 minutes.
For thicker sauce, stir in cornstarch slurry and cook 1 more minute until glossy.
Return chicken to skillet and coat with sauce. Simmer 2–3 minutes, spooning sauce over chicken. Remove from heat and slice after resting briefly.
Build bowls with mixed greens base, cooked quinoa or rice, roasted sweet potatoes, and sliced chicken. Drizzle with extra sauce and add optional toppings.
Serve warm, optionally with lemon wedges to balance the sweetness.