Prepare a big pot of water to boil the tortellini in. Once water is boiling, add tortellini, cook until desired doneness, then drain.
While you're waiting for the water to boil, Heat the olive oil in a separate large skillet over medium heat. Slice the smoked sausage thinly and add it to the skillet and cook until well-browned, 3 to 4 minutes per side. Add the garlic and cook and stir for 30 seconds.
In this order: Add the chicken stock, tomato sauce, heavy cream, and salt and pepper and stir until simmering and bubbly. ** Adding chicken stock first will deglaze the pan, tomato sauce will bring temp down, then it will be safe to add the cream, so it won't break.** Reduce heat and simmer until slightly thickened, 7 to 10 minutes. Stir in the parmesan cheese until melted, then add the frozen peas and heat through.
Now add cooked tortellini to sauce and stir until combined and heated through! Enjoy!
