Mac and Cheese with Ham and Mushrooms

• Adapted from a 1988 Pierre Franey recipe (via The Recipes of Record by Hesser) and J. Kenji López-Alt’s recipe from The Food Lab.
• Béchamel tips from The Food Lab.
• Garnish ideas from this Epicurious video (their food science sucks, though).

Ingredients

• 1 pound macaroni
• Kosher salt
• 1 pound mushrooms, roughly sliced
• 2 large onions, finely sliced
• 1 pound sliced cooked ham, cut into ½-inch cubes
• 10 tablespoons unsalted butter
• ½ cup all-purpose flour
• 4 cups evaporated milk
• Black pepper
• 2 tablespoons Dijon mustard, or more to taste
• ⅛ teaspoon cayenne pepper, or more to taste
• ½ pound sharp cheddar, grated
• ½ pound gouda, grated
• ¼ pound American cheese, thinly sliced
• ¼ pound mozzarella, cubed
• 3 scallions, biased

Substitutions

• Any pasta will suffice, but I like pastas with high surface area (it’s just a vehicle for the cheese sauce, after all) like cavatappi, gemelli or (my favorite) cascatelli. Elbow macaroni is the classic and nostalgic choice.
• Evaporated milk can be substituted with half-and-half (less protein but more fat, which will result in a creamier sauce) or whole milk (less protein and fat than evaporated milk, which will result in a thinner sauce).
• Pre-shredded cheese is not an acceptable substitute for freshly grated cheese: they are covered in anti-clumping agents like potato starch which will prevent it from melting smoothly and evenly, ironically giving you clumps.
• Feel free to mix up the cheeses; see Cooking Notes below. The quantity of cheese is non-optional: you want 1.5 pounds of cheese per pound of macaroni.

Directions

1. Preheat the oven to 375 degrees. Add the macaroni to an empty pot and add enough cold water to cover the macaroni by 1 inch. Add salt until the water tastes like seawater. Cook until macaroni is just shy of al dente, about 2 minutes less than package directions. Drain the pasta, run under cold water to stop the cooking, and set aside.
2. In a skillet, melt two tablespoons butter over medium heat. Add the mushrooms and cook, stirring frequently, until they have given up their liquid and are brown, about 15 minutes. Add the onion and continue cooking, stirring, until the onion is translucent, about 5 minutes. Add the ham and continue cooking, stirring, for another minute. Set aside.
3. In a medium saucepan, melt 8 tablespoons butter over medium heat. Add the flour, whisking until smooth. Lower the heat. Add the evaporated milk in ½-cup portions, whisking until smooth before adding the next portion. Add the salt, pepper, mustard, cayenne and cheeses and whisk until smooth.
4. Transfer the macaroni, mushroom/onion/ham mixture and cheese sauce to a casserole dish, add the cubes of mozzarella and mix well. Top with breadcrumbs, if using. Bake for 20 minutes. Let sit for 10 minutes before serving with scallions.

• Yield: 8–10 servings.
• Time: 1 hour preparation; 1½ hours cooking.

Cooking Notes

• By the end of step three, the cheese sauce is just about the same consistency as you can expect to serve (it will thicken as you bake and as it cools). Add more milk to make thinner, or more cheese or flour to make thicker.
• If the cheese sauce is thin, lumpy or appears broken, it means that the flour is not evenly dispersed throughout the sauce: smooth it out with an immersion blender. This is why we add the milk in portions: it is easier to disperse the flour in a small amount of liquid.
• The cheese sauce is a mixture of water, protein and fat (and emulsifiers/stabilizers). Loosely speaking:
  • More water (mostly via the milk) will make the sauce thinner.
  • More protein (mostly via the cheese) will make the sauce more gooey.
  • More fat (via both the milk and cheese) will make the sauce creamier.
  • Emulsifiers (via the American cheese) and stabilizers (the flour) prevent splitting and allow the sauce to melt evenly. (They work differently from a chemical perspective, but their effect is the same.)
• You can read this recipe in terms of striking this balance.
  • Using evaporated milk or half-and-half instead of whole milk: this lowers the water content of your sauce.
  • Using low-moisture, hard cheeses: they have more protein molecules which are more tightly bound together, and are therefore more gooey when melted. Cheddar, gruyère and gouda are good choices.
  • Using American cheese: American cheese contains emulsifiers and is designed to melt into a smooth, gooey liquid.
• While hard cheeses are stretchy because of their strongly interlocking proteins, stretch-curd cheeses are in a league of their own because they’re plasticized/kneaded and have a fibrous structure. Mozzarella, provolone and halloumi are good choices. I’m not sure if mixing the cubes in at the end is the right move: it may be better to melt it in the sauce, so that the stretchiness.
• Making your own breadcrumbs is a great way to add more texture and seasoning. This can be done ahead of time and stored in an airtight container.