In a large pot of boiling salted water, cook gnocchi according to package instructions; drain well and set aside.
In the meantime, season chicken with salt, pepper, paprika and melt 2 tablespoons of butter in a large skillet over medium heat.
Add chicken thighs to the skillet in a single layer and cook until golden brown and cooked through, reaching an internal temperature of 165ºF (74ºC), about 4-5 minutes per side; remove chicken thighs from the skillet and set aside.
In the same skillet, melt the remaining 3 tablespoons of butter. Add onion, and cook, stirring frequently, until tender, about 2-3 minutes. Stir in garlic, and Italian seasoning until fragrant, about 1 minute.
Gradually whisk in chicken broth, and cook, whisking constantly for about 2 minutes. Stir in whipping cream and shredded mozzarella, until combined and thickened, about 1-2 minutes; season with salt and pepper, to taste.
Stir in gnocchi and spinach until the spinach has wilted, about 1-2 minutes. Return cooked chicken thighs to the skillet with gnocchi and spinach. Serve the spinach chicken gnocchi immediately, with fresh chopped parsley, red chili pepper flakes, and sprinkled parmesan.
