Preheat your oven to 425°F (218°C) with a rack positioned in the middle.
Pat chicken breasts dry with paper towels. If breasts are uneven in thickness, butterfly or pound to an even 3/4-inch thickness.
In a small bowl, combine paprika, garlic powder, thyme, rosemary, 1/2 teaspoon salt, and black pepper to create a seasoning mixture.
Brush chicken breasts with 1 tablespoon olive oil, then apply seasoning mixture evenly to both sides.
Peel sweet potatoes and cut into 3/4-inch cubes of uniform size.
In a medium bowl, toss sweet potato cubes with remaining 1 tablespoon olive oil and 1/2 teaspoon salt until evenly coated.
Line baking sheet with parchment paper. Arrange chicken and sweet potatoes in a single layer, ensuring no overlap.
Place baking sheet in preheated oven. After 15 minutes, remove chicken if internal temperature has reached 165°F (74°C). Continue roasting sweet potatoes for an additional 10-15 minutes until fork-tender.
Allow chicken to rest for 10 minutes before slicing against the grain into 1/2-inch pieces.
Divide chicken and sweet potatoes evenly among 4 meal prep containers. If using, add 1/2 cup fresh spinach and 1 tablespoon pumpkin seeds to each container.
Allow food to cool completely before sealing containers.