Preheat oven to 400 degrees F. Butter an 8x8 casserole dish and set aside.
Bring a large pot of water to a rolling boil; add the broccoli and blanch for 1 minute, then drain well and place in a large mixing bowl.
Melt butter in a deep skillet over medium heat. Saute onion 3-4 minutes, then add the garlic.
Stir in the cream cheese until melted, and then stir in the heavy cream, mustard, salt, pepper, half of the cheddar, and the mozzarella. Once the cheese is melted, pour over broccoli and stir to coat.
Pour the contents into the prepared dish and top with the remaining cheddar. Bake uncovered 15-20 minutes, until cheese is bubbling and golden.
Notes
Leftover are good up until 5 days.
This is perfect to bring for pot lucks and family gatherings.
6 grams total carbs, 1g fiber and 5g net carbs per serving