Ingredients:

  • 1 pound Elbow macaroni or small shells
  • 3 cups Water or low-sodium Chicken Broth
  • 2 tablespoons Unsalted butter
  • 2 tablespoons All-purpose flour
  • 1 cup Whole milk
  • 1/2 teaspoon Mustard powder
  • 1 teaspoon Salt (for cooking)
  • 1/2 teaspoon Black pepper
  • 8 ounces Sharp cheddar, freshly grated
  • 4 ounces Monterey Jack or Gruyère cheese, freshly grated
  • 2 ounces Cream cheese, cut into cubes (optional)

Instructions:

  1. Set the Instant Pot to Sauté mode (Normal setting). Add butter; once melted, whisk in the flour until a smooth paste (roux) forms. Cook for 1 minute until lightly golden.
  2. Whisk in the water/broth, scraping the bottom thoroughly to deglaze any bits stuck to the base. Stir in salt, pepper, and mustard powder. Bring the liquid to a gentle simmer.
  3. Add the dry pasta directly into the simmering liquid. Do not stir vigorously; just ensure the pasta is mostly submerged.
  4. Secure the lid. Set the Vent to Sealing. Pressure Cook on High Pressure for 4 minutes.
  5. Once the timer finishes, allow a 5-minute Natural Pressure Release (NPR). After 5 minutes, manually quick release any remaining pressure.
  6. Remove the lid and switch the Instant Pot to Keep Warm or Sauté (Low setting) if the liquid seems too thick.
  7. Crucial Step: Gradually add the grated cheeses (and cream cheese, if using) in small handfuls, stirring continuously until each batch is completely melted and smooth before adding the next. Do not let it boil during this stage.
  8. Taste and adjust seasoning (more salt/pepper if necessary). Serve immediately while piping hot and glossy.