► Preheat oven to 400°F
► In a medium saucepan, melt butter over medium heat. Add pork belly and cook until browned and crispy. Remove from pan and set aside.
► To the same pan, add shallot, reduce heat to low, and slowly cook, stirring frequently until lightly browned, about 5 minutes. Add jalapeño slices and continue cooking until slices have softened, another 5 to 7 minutes.
► Sprinkle flour over shallot and jalapeño and cook, stirring often, for 3 minutes. While whisking constantly, add heavy cream; simmer for 5 minutes (mixture will thicken).
► Slowly add Jarlsberg and whisk until smooth and melted, then stir in parmesan cheese. Season with salt and pepper to taste.
► Fold in the cooked pasta, pork belly, and jalapeño. Toss to mix well.
► Place in a 9 x 13-inch baking dish; sprinkle with additional Jarlsberg cheese. Bake for 15 minutes. Serve immediately.