01 -
Fill a large pot with water, add a generous amount of salt, and bring to a boil over medium-high heat.
02 -
Finely grate the Parmesan cheese if using block cheese. Finely grate or mince the garlic cloves.
03 -
Melt unsalted butter in a large nonstick frying pan or skillet over medium heat. Add garlic and cook until fragrant but not browned, about 30 seconds.
04 -
Pour in the half-and-half and bring mixture to a gentle simmer. Add the grated Parmesan, kosher salt, and several grinds of black pepper. Whisk until smooth and just simmering, then remove from heat.
05 -
Place tortellini into the boiling water and cook, stirring occasionally, for 2 minutes less than package directions. Reserve 120 millilitres of pasta water, then drain tortellini.
06 -
Add drained tortellini to the sauce and cook over medium heat, stirring frequently, until heated through and the sauce slightly thickens, about 2 minutes. Adjust consistency with some reserved pasta water if necessary.
07 -
Taste for seasoning; add more kosher salt and black pepper as needed. Garnish with finely chopped fresh parsley if desired. Serve immediately.