Preheat your Kamado Joe Pellet Joe to 400ºF.
Preheat a Lodge 10” Cast Iron Skillet on the grill.
When the skillet is hot, add the pancetta. Cook until the fat is rendered out and the pancetta begins to brown. Add the Brussels sprouts, shallots, garlic, thyme, Saica Extra Virgin Olive Oil and Cattleman’s Grill Trail Dust All Purpose Seasoning and toss well to mix.
Close up the grill and cook until the sprouts begin to soften and brown, about 45 minutes.
Combined the heavy cream and Kozlik’s Dijon Classique Mustard. Whisk to combine. Pour over the Brussels sprouts.
Add the cheeses and heavy cream mixture to the skillet and stir.
Sprinkle the bread crumbs over the top evenly. Continue cooking until the top is browned and the gratin is bubbling up through the topping in the center of the skillet, about 30 minutes more.
Remove from the grill and serve hot.