In the time it takes to boil water and cook the pasta and asparagus in one pot, you can make the sauce in another. Set a large pot of water to boil over high heat. Preheat a large skillet or Dutch oven over medium heat and brown the sausage until fully cooked, about 7 to 9 minutes.
Meanwhile, when the water is boiling, add a good pinch of salt and add your ravioli AND the cut up asparagus and cook together for 3 to 5 minutes. Check your package cooking instructions, mine was 3 minutes but it took a bit longer with the asparagus. Taste one to check. BEFORE DRAINING, pull out about a cup of the starchy cooking liquid and reserve it for the sauce. You can do this with a coffee mug, a ladle, or a measuring cup.
When the sausage is fully browned, stir in the garlic. Then add the cream and let it simmer and reduce over low heat while your pasta and asparagus finish cooking, about 5 minutes. Stir occasionally, it can bubble a little but should not be boiling.
When the cream has thickened a bit, add the frozen peas, salt, pepper, the leaves off of 2 or 3 sprigs of thyme, half of the Parmesan cheese, and about ½ cup of the starchy cooking liquid. Stir well to combine, keeping it over low heat to continue thickening the sauce.
Add the drained pasta and asparagus to the sauce and stir well to combine over low heat. You can add more of the pasta water as needed if your sauce becomes too dry. Top with the rest of the Parmesan cheese and more thyme leaves to garnish and serve.