Step 1: Brown the Sausage. Heat 1 tablespoon of olive oil in a large skillet over medium-high heat. Once the oil glimmers, add sliced smoked sausage and brown it for about 5-7 minutes until caramelized.

Step 2: Sauté Garlic. Remove the browned sausage and set it aside. In the same skillet, add 2 tablespoons of butter and 2 teaspoons of minced garlic. Sauté the garlic for 30 seconds until fragrant.

Step 3: Prepare the Sauce. Pour in 4 cups of chicken broth and 1 cup of milk while scraping up the browned bits. Add in 2 tablespoons of ranch seasoning, stirring well. Bring to a simmer for around 3-5 minutes.

Step 4: Cook the Pasta. Add 12 ounces of dry rotini directly into the skillet, ensuring it's submerged in the sauce. Cover and reduce heat to medium-low, stirring occasionally for about 12-15 minutes until al dente.

Step 5: Incorporate Cheese. Once the pasta is cooked, reduce heat to low and stir in 2 cups of shredded white cheddar cheese, mixing continuously until melted and creamy.

Step 6: Add Vegetables. Sprinkle in 2 cups of fresh spinach and 1 cup of roasted red peppers, stirring gently until the spinach wilts, about 2-3 minutes.

Step 7: Combine and Season. Return the browned sausage to the skillet, mix well, and season with salt and pepper. Let sit for an additional minute before serving.