2tablespoonsparsleyfinely chopped, for garnish (optional)
Lemon wedgesfor serving
Preheat the oven to 400°F with a rack placed in the center of the oven. Lightly brush a baking dish with olive oil and set aside.
Heat 1 tablespoon olive oil over medium-low heat. Add the onions, garlic, and bell peppers, and season with salt and pepper. Cook until the onions have wilted then stir in the spinach, one cup at a time.
Stir in the cooked quinoa and season to taste with salt and pepper.
Season the sole lightly on both sides with salt and pepper. Lay the sole flat side up. Divide the stuffing between the fillets.
Roll the sole and place in prepared baking dish. Lightly brush the tops with olive oil and sprinkle with paprika.
Bake in the oven for about 15-20 minutes, or until the fish flakes easily with the tip of a knife. Garnish with parsley and serve with a squeeze of lemon.