Cook the pasta in salted water until al dente, drain and set aside. Take skin off the brie cheese and dice. (The cheese should be at fridge temperature, and not be too ripe.) Melt butter in pan with garlic, taking care not to burn it. Add the brie and sliced chorizo to the pan. Cook until bubbles form in the cheese, but before it starts to caramelise. Deglaze the pan with sherry, and season with salt and pepper. Add cream, grated pecorino cheese and cooked penne. Reduce heat and heat through.