Bring a large pot of water to a boil. Cook tortellini according to package instructions to al dente. They cook very fast, so make sure to drop them in the boiling water once everything else is almost ready. Reserve a cup of pasta water before draining.

While you wait for the water to boil, brown the sausage in a large skillet over medium heat, breaking up with a wooden spoon, along with the onions and minced garlic. Once browned, keep warm on low heat until you toss everything together.

In a medium bowl whisk together eggs, heavy cream, 3/4 cup Parmesan cheese (reserve 1/4 cup for garnish), salt and pepper.

Once tortellini is cooked, drain and add to sausage mixture. Pour in the egg, cream, and cheese mixture and toss to coat. Once heated through, taste for seasoning, serve immediately. The heat of the pasta should warm the sauce, do not over-heat the sauce or you will get scrambled eggs. Garnish with additional cheese.