Preheat the oven to 350°F. Have an 8x8" baking dish ready (no need to grease or oil it).
Add the diced bacon to a cold skillet. Turn the heat up to medium and cook, stirring occasionally, until mostly cooked through and crispy. Remove bacon with a slotted spoon and drain on paper towels.
If there is a lot of bacon grease leftover, drain some, but leave enough to cook the onions. Add the diced onions and minced garlic to the pan and saute until translucent, fragrant, and slightly browned. Remove from heat and set aside.
In a large mixing bowl, add the cream cheese, mayo, MCT oil, cooked onions, jalapeño, half of the shredded cheese, salt, and pepper. Using a firm silicone spatula or a wooden spoon, evenly mix everything together.
Add in the cooked chicken pieces, broccoli, and macadamia nuts. Stir to coat everything and pour into the 8x8" baking dish. Sprinkle the cooked bacon over the casserole evenly. Evenly spread the remaining shredded cheese on top of the bacon.
In a small bowl, combine the crushed pork rinds and melted butter with a fork until everything is evenly combined. Pour over the casserole and spread evenly across the entire surface.
Bake in the preheated oven for 30 minutes, or until the edges are bubbly and browned.