Directions

1. Preheat oven to 350° F if baking right away (optional: you can also cover and refrigerate or freeze for another day). Lightly grease a 9×13" baking dish.
2. Melt the butter in a medium skillet over medium-high heat.
3. Add the onion and cook until softened and translucent. Stir in garlic, Italian seasoning, salt, and pepper and cook 1 minute.
4. Stir in the flour until no white streaks remain. Cook 1 minute.
5. Whisk in the milk and broth, and cook over medium heat until thickened, stirring constantly. This should take between 5-10 minutes.
6. Meanwhile, cook the penne pasta to al dente in a large pot of boiling, salted water (according to package directions). Drain.
7. Combine cooked pasta, thickened sauce, and sliced kielbasa in baking dish and stir well.
8. Top with shredded cheese and bake until bubbly, about 20-25 minutes. You can also place in the refrigerator to cool, then cover and refrigerate up to 4 days or freeze up to 3 months.