Preheat oven to 400 degrees F and line a baking sheet with parchment paper

Rinse the cauliflower in cold water and pat dry with paper towels. 

Place the cauliflower on a cutting board and slice in 1/4 inch slices, across
the head. You want thick slices, about the thickness of chicken cutlets.

Place the cauliflower on the baking sheet, and sprinkle with garlic salt and pepper.

Add butter and olive oil to a saucepan and heat over medium heat. 

After the butter melts, add the onion. Saute for about 5 minutes, until golden brown. 

Add the minced garlic and saute for 1 additional minute. 

Turn the heat to low and add the tomato sauce, Italian seasoning, coarse ground garlic salt,
salt, pepper, and brown sweetener Stir until well combined.

Turn heat to medium-high and heat until bubbly. 

Spoon sauce over cauliflower slices on the baking sheet. You want the cauliflower totally covered.

Top the slices with a generous amount of shredded Parmesan cheese. 

Bake for 30 - 45 minutes, making sure the Cauliflower slices are golden brown on the
bottom and the sauce and cheese are thick and browned well. 

Remove from the oven and let them cool for 2-3 minutes.