Heat a large skillet over medium heat.

Add both sweet and hot Italian sausage and chopped onion to the skillet.

Cook until the sausage is fully cooked and browned, breaking it up with a spoon.

Drain excess grease from the skillet and wipe it clean with paper towels.

Return the skillet to the burner with the cooked sausage and onion.

Add the Swiss chard (torn into bite-size pieces) and minced garlic to the skillet.

Reduce heat to medium-low, cover the skillet, and cook for about 15 minutes, stirring occasionally, until the Swiss chard is tender.

While the Swiss chard is cooking, bring a large pot of salted water to a boil.

Add penne pasta to the boiling water and cook according to package directions until al dente.

Drain the cooked pasta.

Add the drained pasta to the skillet with the sausage and Swiss chard.

Pour in the heavy cream and sprinkle with nutmeg.

Stir until everything is well combined and heated through.

Serve immediately, sprinkled with Parmesan cheese.