In a large skillet over medium-high heat, melt 1/4 cup of the butter. Add the cubed chicken and season with salt, pepper, and paprika. Cook for about 5-7 minutes, stirring occasionally, until the chicken is golden brown and cooked through.
Reduce the heat to medium and add the remaining butter to the skillet. Once melted, stir in the minced garlic, Italian seasoning, and crushed red pepper flakes, cooking for about 1 minute until fragrant.
Pour in the chicken broth and bring the mixture to a simmer. Let it cook for 3-4 minutes, allowing the flavors to meld.
Stir in the heavy cream and Parmesan cheese, mixing until the sauce is smooth and creamy. Continue to simmer for another 2-3 minutes, adjusting the seasoning as needed.
Add the fresh spinach and cherry tomatoes to the skillet, stirring until the spinach wilts. This should take about 2 minutes.
Remove the skillet from heat and serve immediately, garnishing with additional Parmesan if desired.