-12 ounces Fontina and/or aged cheddar cheese
-6 garlic cloves
-2 large sprigs of sage
-1 bunch of broccoli rabe
-¼ cup plus 1 tablespoon extra-virgin olive oil
-1 pound sweet or hot Italian sausage (can replace with a plant-based sausage option)
-½ teaspoon crushed red pepper flakes
-2 cups half-and-half
-1 pound ridged medium pasta shells, or large tube pasta, such as lumaconi or rigatoni
1.Place racks in center and upper third of oven; preheat to 325°. Heat a large pot of water over high. Add a few tablespoons of salt and bring to a boil (this is for your pasta).
2.Grate 12 oz. Fontina cheese on the large holes of a box grater (you should have about 4½ cups). Smash 6 garlic cloves, peel, and coarsely chop. Pick all sage leaves from stems and set aside about 10. Finely chop remaining leaves (you should have about 1 Tbsp.). Trim tough dried ends from 1 bunch of broccoli rabe, then cut stems into 2″ pieces. Leave leafy ends long.
3.Heat a deep, large, ovenproof skillet, preferably cast iron, over medium-high. Add ¼ cup oil and swirl to coat. Remove 1 lb. sausage from casings and add to skillet. Break into small pieces with a wooden spoon. Cook, undisturbed, until sausage is browned, about 4 minutes. Stir a couple of times and continue to cook, undisturbed again, until sausage is fully cooked through, about 3 minutes longer.
4. Add garlic, chopped sage, and ½ tsp. red pepper and cook, stirring, until garlic is golden, about 2 minutes.
5. Stir in 2 cups half-and-half and simmer until sauce is slightly thickened about 2 minutes. Reduce heat to low.
6.Gradually add about two-thirds of cheese, bit by bit, stirring constantly and letting cheese melt completely before adding more, until sauce is smooth and thick, about 3 minutes; season with salt and remove from heat.
7.Meanwhile, cook 1 lb. pasta shells in boiling salted water 2 minutes shy of package instructions (8–10 minutes depending on the type). During the last 2 minutes, add all of broccoli rabe to pot with pasta. Drain in a colander and shake several times to remove excess water. Return pasta and broccoli rabe to empty pasta pot.
8.Add cheesy sausage mixture from skillet to pot with pasta. Stir until pasta and broccoli rabe are coated in sauce, then transfer everything back to skillet.
9.Cover skillet tightly with foil and bake on center rack until pasta is tender and sauce is bubbling, 30–40 minutes. Let rest a few minutes while you heat broiler.
10.Remove foil and top with remaining cheese. Toss sage leaves with remaining 1 Tbsp. oil in a small bowl and arrange over pasta. Broil until cheese is browned and bubbling in spots, about 5 minutes (depending on strength of broiler).