Step 1: Sauté the Kielbasa

1. Heat olive oil or butter in a large pot or Dutch oven over medium heat.
2. Add the sliced kielbasa and cook for 3-4 minutes, stirring occasionally, until the sausage is browned and slightly crispy. Remove the kielbasa and set aside on a plate.

Step 2: Sauté the Aromatics

1. In the same pot, add the diced onion and sauté for 2-3 minutes until softened.
2. Stir in the minced garlic and cook for another 30 seconds, being careful not to burn it.

Step 3: Add Liquid and Pasta

1. Pour in the chicken broth and heavy cream, stirring to combine.
2. Add the uncooked pasta, smoked paprika, salt, and black pepper. Stir well to ensure the pasta is submerged in the liquid.

Step 4: Simmer the Pasta

1. Bring the mixture to a gentle boil, then reduce the heat to low. Cover the pot and let the pasta simmer for 10-12 minutes, stirring occasionally to prevent sticking.
2. If adding vegetables like peas or broccoli, stir them in during the last 5 minutes of cooking.

Step 5: Make It Creamy

1. Once the pasta is cooked to al dente and most of the liquid has been absorbed, stir in the cooked kielbasa.
2. Gradually add the cheddar and Parmesan cheeses, stirring until melted and the sauce becomes thick and creamy.

Step 6: Garnish and Serve

1. Taste the dish and adjust seasoning with additional salt, pepper, or red pepper flakes if desired.
2. Sprinkle with fresh parsley and serve immediately with extra Parmesan on the side.