In a bowl, mix together the salt, pepper, garlic powder, onion powder, and paprika. Toss the chicken pieces in the spice mix until they're fully coated.
In a large skillet, heat the olive oil over medium-high heat. Add the chicken and cook until golden and no longer pink in the center, about 5-7 minutes. Remove the chicken from the skillet and set it aside.
In the same skillet, melt 2 tablespoons of butter. Add the minced garlic and sauté for about 1 minute until fragrant.
Add the chicken broth, scraping the bottom of the skillet to loosen any browned bits. Bring the mixture to a boil and let it reduce for about 2-3 minutes.
Lower the heat to medium and add the heavy cream, lemon juice, lemon zest, oregano and red pepper flakes. Let it simmer for about 5 minutes until the sauce starts to thicken.
Stir in the remaining 2 tablespoons of butter and the spinach. Cook until the spinach wilts.
Return the chicken to the skillet, making sure to coat all the pieces in the sauce. Simmer for an additional 2-3 minutes until the chicken is heated through.
If desired, sprinkle with freshly grated Parmesan cheese before serving. Serve over rice or noodles.