Slice sausage in 1/4-inch slices.
Heat a large skillet over medium-high heat. Brown sausage well. Remove from pan; set aside.
Return pan to heat and deglaze pan with the 1 1/2 cups water. Add the pasta. Bring to a boil, cover and reduce heat. Cook until water is absorbed by pasta (about 8 minutes).
Add the cream, peas, parmesan and cajun seasoning to the pan; stir well. Add the browned sausage back to the pan; heat through.
Top with sliced green onion and grape tomatoes. Serve immediately.
Serves 2-4, depending on appetite and accompanying dishes.