- 8 Ounces (about 2 1/2 cups) mezzi rigatoni or fusilli pasta
- 2 Tablespoons olive oil
- 1 Tablespoon butter or bacon fat
- 1/2 large sweet onion, very thinly sliced
- 1/3 Cup flour
- 2 Cups nonfat milk
- 1/2 Cup half-and-half or heavy (whipping) cream
- 1/2 Teaspoon salt
- 1 Teaspoon hot red pepper sauce, plus more for serving
- 1 Cup (3 ounces) shredded white cheddar cheese
- 1 Cup (3 ounces) shredded Gruyere or Swiss cheese
- 1 1/2 Cup (4 to 5 ounces) small dice corned beef (or smoky ham)
- Chopped parsley and green onions, for garnish
Step 1: Have all ingredients ready and set near the cooking surface.
Step 2: Heat a large pot of salted water to boil over high heat. Add 8 ounces pasta. Cook, stirring often, until al dente (nearly tender but not soft when tasted), 8 to 10 minutes. Scoop out 1 cup of the cooking liquid and reserve it. Drain the pasta well and let stand while you make the sauce.
Step 3: While the pasta cooks, heat 2 tablespoons olive oil and 1 tablespoon butter or bacon fat in a medium-size saucepan over medium heat. Add ½ large sweet onion, thinly sliced; cook and stir until onion is golden brown, 5 to 8 minutes.
Step 4: Sprinkle 1/3 cup flour over onions; cook and stir for 1 minute. Whisk in 2 cups nonfat milk and ½ cup half-and-half (or whipping cream) and ½ teaspoon salt. Cook, whisking constantly until milk thickens, about 3 minutes. Remove from heat and season with 1 teaspoon red pepper hot sauce.
Step 5: When pasta is done, stir both cheeses into the hot white sauce. Add drained pasta and corned beef; mix gently. Taste for salt. Gently stir in enough of the reserved pasta cooking liquid to loosen up the mixture. Serve right away sprinkled with parsley and onions.