1. Start by bringing a pot of salted water to a boil. Cook the penne pasta according to the package instructions. During the last 2 minutes of cooking, add the broccoli florets to the pot. Drain the pasta and broccoli mixture and set it aside.

2. In a large skillet over medium heat, melt the butter. Add the sliced kielbasa and sauté until it’s lightly browned, about 5-7 minutes.

3. Once the kielbasa is seared, stir in the diced onion and minced garlic, and cook until the onion is soft and translucent, about 3-4 minutes.

4. In a small bowl, whisk the cornstarch into the whole milk until fully combined. Pour this mixture into the skillet and bring it to a simmer, stirring constantly. Allow the sauce to thicken, which should take about 2-3 minutes. Once the desired consistency is reached, reduce the heat to low.

5. Add the cooked pasta and broccoli to the skillet with the kielbasa and creamy sauce. Gently toss the ingredients to ensure they’re evenly coated. Season with salt and pepper to taste. Finally, sprinkle the shredded cheddar cheese over the top, allowing it to melt.