01 - Preheat the oven to 425°F. Line a large baking sheet with parchment paper.
02 - In a bowl, toss halved baby potatoes with 1 tbsp olive oil, 1/2 tsp paprika, 1/4 tsp salt, and 1/4 tsp pepper. Spread evenly on the prepared baking sheet.
03 - Roast potatoes for 15 minutes until beginning to soften.
04 - While potatoes roast, combine chicken breasts with remaining 1 tbsp olive oil, remaining paprika, garlic powder, oregano, remaining salt and pepper, and lemon juice. Let marinate for 10 minutes.
05 - Add red bell pepper and red onion to the potatoes on the baking sheet. Toss gently to combine, then return to the oven and roast for an additional 15 minutes or until potatoes are golden and tender.
06 - Heat a grill pan or skillet over medium-high heat. Grill marinated chicken for 5-6 minutes per side, or until cooked through and juices run clear. Transfer to a plate and let rest for 5 minutes, then slice into strips.
07 - Arrange fresh spinach leaves in serving bowls. Top with roasted potatoes, sliced grilled chicken, roasted peppers and onions, and cherry tomatoes.
08 - Sprinkle with chopped fresh parsley and serve immediately with lemon wedges on the side, if desired.