Ingredients:

  • 1 lb (450 g) Medium Shells (Conchiglie) or Elbow Macaroni
  • Salt (Kosher or Sea), for boiling water
  • 4 Tbsp (60 g) Unsalted Butter, divided
  • 4 Tbsp (30 g) All-Purpose Flour (Plain Flour)
  • 3 cups (710 ml) Whole Milk
  • ½ cup (120 ml) Heavy Cream (Double Cream)
  • 1 tsp (5 ml) Dijon Mustard
  • 1 tsp (5 g) Dry Mustard Powder
  • ½ tsp (2.5 g) Smoked Paprika
  • 1 tsp (5 g) Kosher Salt
  • ¼ tsp (1.2 g) Freshly Ground Black Pepper
  • 8 oz (225 g) Sharp Yellow Cheddar, freshly grated
  • 4 oz (115 g) Monterey Jack, freshly grated

Instructions:

  1. Grate the cheddar and Monterey Jack cheeses immediately and set aside. Crucial: Do not use pre-shredded cheese.
  2. Bring a large pot of salted water to a rolling boil. Add pasta and cook according to package directions, subtracting 1 minute from the recommended cooking time (it should be very al dente).
  3. Before draining, scoop out 1 cup (240 ml) of the starchy pasta cooking water. Drain the pasta and set aside.
  4. Make the Roux: Melt the butter in the heavy-bottomed saucepan over medium heat until foamy. Sprinkle in the flour and whisk constantly for 90 seconds to 2 minutes until the mixture (the roux) looks sandy and smells slightly nutty. Do not let it brown.
  5. Add Dairy: Remove the pan from the heat briefly. Slowly pour in the whole milk, whisking continuously to prevent lumps from forming. Once smooth, whisk in the heavy cream.
  6. Simmer and Thicken: Return the pan to medium-low heat. Continue to whisk occasionally. Bring the mixture just up to a gentle simmer (small bubbles around the edge). Cook for 5–8 minutes, stirring frequently, until the sauce coats the back of a spoon thickly (this is the Béchamel).
  7. Season the Sauce: Reduce the heat to the lowest possible setting. Whisk in the Dijon mustard, dry mustard powder, smoked paprika, salt, and pepper until combined.
  8. Incorporate Cheese (The Creaminess Key): Remove the saucepan completely from the heat. Wait 30 seconds. Add the grated cheese blend to the sauce, one handful at a time, stirring gently after each addition until fully melted and smooth. Note: Do not allow the sauce to boil after the cheese is added, or it will seize and become grainy.
  9. Adjust Consistency: If the sauce is too thick, whisk in a splash or two of the reserved pasta water until the desired ultra-creamy consistency is achieved. Taste and adjust salt and pepper as needed.
  10. Combine: Add the reserved, drained pasta to the cheese sauce. Stir gently until every piece of pasta is thoroughly coated. Serve immediately.