Instructions
Make the mac and cheese Begin by bringing a medium saucepan filled with generously salted water — akin to seawater in saltiness — to a rolling boil. This seasoning enhances the pasta's flavor right from the start. Add the macaroni and cook, stirring occasionally, until it reaches al dente perfection, about 8 to 10 minutes or following the package instructions. The pasta should be tender yet retain a pleasant chew. While the pasta cooks, whisk together in a small bowl the plain flour, mustard powder, garlic powder, kosher salt, freshly ground black pepper, and a pinch of cayenne pepper. This mixture will form the flavorful base of your cheese sauce. Once your pasta is cooked, drain it thoroughly using a colander. Return the empty pan to low heat and melt 6 tablespoons of butter in it. When the butter has fully melted, whisk in the seasoned flour mixture. Keep stirring frequently for about 1 minute until the mixture develops a light golden-brown hue and emits a warm, nutty aroma—this signals that the roux is ready. Be vigilant to prevent scorching. Gradually whisk in the whole milk and heavy cream, ensuring a smooth blend with no lumps. Continue cooking the sauce while whisking constantly until it thickens slightly and warms through, about 2 minutes. Remove the pan from heat. Slowly incorporate the shredded Monterey Jack cheese, stirring continuously with a wooden spoon or silicone spatula until completely melted and smooth. Finally, fold in the drained macaroni, coating it thoroughly with the luscious cheese sauce. Prepare a 9-by-13-inch rimmed baking sheet by lining it with parchment paper or aluminum foil, then lightly grease the surface with nonstick spray or butter to prevent sticking. Pour the warm mac and cheese mixture onto the prepared sheet, spreading it evenly with a spatula. Cover the surface with another piece of greased parchment paper, oiled side down directly touching the mac and cheese. Place the tray in the refrigerator and chill until the mac and cheese is firm and cool, about 1 hour. This step makes it easier to handle when assembling the sandwiches. Make the grilled cheese sandwiches Preheat a large cast-iron or nonstick skillet over medium-low heat, allowing ample time for it to reach an even temperature without burning the butter. In a small bowl, blend together 4 tablespoons of butter and 1 teaspoon of garlic powder until well combined. This garlic butter will infuse the bread with a wonderful aroma and golden crispness. Remove the chilled mac and cheese block from the refrigerator and carefully peel off the top layer of parchment paper. Using a sharp knife, cut the block into 8 equal pieces, each one destined to become a hearty sandwich filling. To store extras, individually wrap each portion in double layers of resealable plastic bags; refrigerate for up to 3 days or freeze for up to 1 month. Take the 16 bread slices, and spread approximately 3/4 teaspoon of the garlic butter on one side of each slice. Arrange half of the slices, buttered side down, on a clean cutting board. Layer each slice with one slice of mild Cheddar cheese, then one piece of the mac and cheese block. To transfer the mac and cheese pieces gently from the baking sheet, use a spatula or slide your hand below the piece and carefully flip it onto the sandwich without breaking. Next, top each with a slice of Monterey Jack cheese, then finish the sandwich with the remaining bread slices, buttered side up. Carefully place as many sandwiches as fit into the hot skillet without crowding. Cover the pan to trap heat and cook until the bottoms turn a beautiful golden brown, about 4 minutes. Flip each sandwich and continue to cook, covered, until the other side is equally browned, the cheese inside is melted, and the mac and cheese filling is warmed through—another 4 minutes. Repeat this process with the remaining sandwiches. For a neat presentation and easier eating, slice each sandwich in half if you like. Serve immediately and enjoy the comforting, cheesy goodness.
