1. Fill a large pot with water and add a generous pinch of salt.
2. Bring the water to a rolling boil over high heat.
3. Add 16 oz of pasta to the boiling water.
4. Cook the pasta according to package instructions until al dente, usually 8-10 minutes.
5. Reserve 1 cup of pasta water before draining.
6. Drain the pasta in a colander and set aside.
7. Heat 2 tablespoons of olive oil in a large skillet or Dutch oven over medium heat.
8. Add the diced onion to the pan and sauté for 2-3 minutes until translucent.
9. Add minced garlic and cook for another 30 seconds until fragrant.
10. Increase the heat to medium-high and add 1 lb of spicy Italian sausage (casings removed).
11. Break up the sausage with a wooden spoon and cook for 5-7 minutes until browned and cooked through.
12. If using any optional vegetables like bell peppers or mushrooms, add them now and cook for an additional 2-3 minutes.
13. Reduce the heat to medium-low once sausage and vegetables are fully cooked.
14. Add 2 cans of Rotel diced tomatoes with green chilies to the skillet with the sausage mixture.
15. Stir in 8 oz of softened cream cheese, breaking it into smaller pieces to help it melt evenly.
16. Pour in 1 cup of heavy cream and stir to combine.
17. Add 1 ½ cups of shredded cheddar cheese, reserving ½ cup for topping.
18. Stir the sauce continuously until the cheese is fully melted and the sauce is smooth.
19. Season the sauce with salt and black pepper to taste.
20. Gradually add some reserved pasta water if the sauce is too thick, adjusting to your desired consistency.
21. Add the cooked pasta to the skillet with the Rotel sauce.
22. Gently fold the pasta into the sauce, ensuring each piece is well-coated.
23. Let the pasta simmer in the sauce for 2-3 minutes to absorb the flavors.
24. If desired, transfer the pasta to a large baking dish.
25. Sprinkle the remaining ½ cup of shredded cheddar cheese over the top of the pasta.
26. Optional: Place the dish under the broiler for 2-3 minutes until the cheese is melted and bubbly.
27. Remove the Rotel pasta from heat (or oven if broiled).
28. Let it cool for a few minutes before serving.
29. Garnish with chopped fresh herbs like parsley or cilantro if desired.
30. Serve hot and enjoy your flavorful and creamy Rotel Pasta.