01 - Preheat oven to 425°F. Line a large baking sheet with parchment paper.
02 - In a bowl, whisk together Dijon mustard, maple syrup, olive oil, garlic, vinegar, salt, and black pepper. Add chicken breasts and toss to coat. Marinate for at least 15 minutes.
03 - On the prepared sheet, toss sweet potato cubes with olive oil, paprika, and salt. Spread in an even layer. Roast for 25-30 minutes, flipping halfway, until tender and golden.
04 - Heat a grill pan or skillet over medium heat. Remove chicken from marinade and grill or sear for 6-7 minutes per side, until cooked through and juices run clear. Let rest for 5 minutes, then slice.
05 - In a small bowl, whisk together dressing ingredients: Dijon mustard, maple syrup, olive oil, lemon juice, salt, and pepper.
06 - Arrange spinach or greens in 4 large bowls. Top each with roasted sweet potato, cherry tomatoes, red onion, and sliced chicken. Drizzle with dressing and add optional toppings like feta, parsley, or pumpkin seeds.