Heat oil in medium sized skillet to medium heat. Slice sausage coins in half, then add to the pan. Cook sausage, turning occasionally, until brown on all sides and fully cooked. Remove to a bowl lined with paper towels. Set aside.
Bring a pot of salted water to a boil. Add pasta and cook until tender with a bite, about 9 minutes. Drain and hold in the strainer.
Bring a heavy-bottomed sauce pan to medium-low heat and add butter. Once melted, add shallots, garlic and Cajun seasoning. Stir to combine. Stir in lemon juice. Slowly add cream, stirring continually. Reduce heat; let the sauce simmer to thicken for about 3 minutes.
Remove from heat and stir in Parmesan. Add sausage to the sauce, then stir in noodles. Serve in shallow bowls with green onion or parsley garnish.
