Grease a casserole dish, add the sliced sausage, and set it aside.
Melt 2 tablespoons of butter in a heavy sauce pan.
Add the onion, peppers, and celery and saute until soft and caramelized on the edges.
Remove the vegetables from the pan and spoon over the sausage.
Cover with the green beans.
Set aside.
Cheese Sauce
Add the remaining butter to the pan and melt it over medium heat.
Whisk in the flour, garlic, paprika, and mustard -- stirring for 2 minutes.
Pour in the milk, whisking constantly until smooth.
Simmer for 2 minutes or until the sauce thickens.
Add the cream cheese and cheddar and whisk until smooth.
Quick Cheese Sauce
Mix the soup and cheese.
Heat until smooth in the microwave.
Stir.
Assembly
Pour the cheese sauce over the vegetables and sausage.
Top with the mashed potatoes.
Sprinkle with a little more grated cheese.
Bake for 15 minutes, or until piping hot and lightly browned on the top.
Notes
Storage:Store cooled shepherd's pie in an airtight container and refrigerate it for four to five days. You can also just wrap the baking dish with plastic wrap or foil.Alternatively, double wrap the leftovers in plastic and freeze them for two to three months.Tips:
Making the cheese sauce in the same pan that you cooked the veggies imparts more flavor into your sauce! So, don't feel the need to wipe down the pan in between, unless something stuck and started to burn.
Use red, yellow, or orange bell peppers with four bumps on the bottom, rather than three. Typically, they're sweeter!
When making the roux for your cheese sauce, start with the whisk, but switch to a wooden spoon—preferably one with a flat edge. That way, you can scrape up any bits that stick to the pan before it scalds or burns.