In a large bowl, combine ground turkey and ground chicken, adding in grated cheese, minced garlic, Italian seasoning, crumbled bouillon cube, red chili pepper flakes, chopped cilantro, and black pepper. Mix thoroughly with your hands until evenly combined. Form the mixture into medium-sized balls, about 1 inch in diameter, then set them aside on a plate.

Heat a tablespoon of olive oil in a large skillet over medium-low heat. Carefully add the meatballs to the hot oil, ensuring they are not overcrowded. Cook for 8-10 minutes, gently turning them every few minutes, until they are browned on all sides and reach an internal temperature of 165°F. Once cooked, remove them from the skillet and set aside.

Using the same skillet, melt 2 tablespoons of butter over medium heat. Add minced garlic and sauté for about 30 seconds until fragrant, then stir in diced onion. Cook for 3-4 minutes or until the onion becomes translucent.

Stir in sun-dried tomatoes into the skillet, frying them for 1-2 minutes. Pour in 1 cup of vegetable broth, scraping the bottom of the pan to deglaze it. Bring the mixture to a simmer and let it reduce slightly for about 3-4 minutes.

Lower the heat to medium-low and add 1 cup of heavy cream to the skillet, stirring continuously. Allow the sauce to simmer gently for 3-5 minutes, until it thickens slightly. Season with salt and pepper to taste.

Once thickened, stir in 3 cups of fresh baby spinach for about 2 minutes, then add ½ cup of grated Parmesan cheese until completely melted.

Reintroduce the cooked meatballs back into the skillet, spooning the sauce over them. Allow to simmer together for an additional 2-3 minutes on low heat.