Melt 1 tbsp butter in a 10.25 oven-safe skillet. (I use a cast-iron skillet)
Season sliced chicken with salt & pepper before placing the chicken in the skillet. Sear on both sides.
Cover the skillet with a lid and simmer on low until the chicken is no longer pink.
Remove chicken from the skillet and set aside.
Deglaze the pan by pouring 2 tbsp chicken broth into the hot skillet then scraping the bits off the bottom with a wooden spoon. Leave the bits in the pan as they are extra flavorful.
Pop the broccoli in the microwave and follow package directions to steam. Or, if you prefer, you can steam in boiling water on the stove.
While the broccoli is cooking, add 2 tbsp butter to the skillet along with the minced garlic. Saute 2 minutes or until fragrant.
Add softened cream cheese, heavy whipping cream, and Italian seasoning to the minced garlic, then stir continuously with a whisk on medium heat until the ingredients are thoroughly combined.
Reduce to a medium/low heat and allow the sauce to simmer gently boiling until the heavy whipping cream has reduced and thickened. Keep whisking so that it doesn't stick to the bottom of the pan. It will take a few minutes for the sauce to reduce and thicken.
Once it has thickened, add the parmesan and pepper jack cheese then continue to stir until the cheeses melt and the sauce is smooth.
Drain steamed broccoli.
Add the chicken and broccoli to keto alfredo sauce and stir until thoroughly combined.
Sprinkle mozzarella cheese on the low carb chicken alfredo broccoli mixture then sprinkle basil on top.
Pop the skillet in the oven on the top rack under broiler for 1-2 minutes or until the mozzarella cheese begins to bubble. While you could leave it on the stove to melt, I found that baking the cheese from the top in the oven produced the best results for this dish.