freshly ground black pepper, to taste and divided (I always use mixed peppercorns)
2lbs.(907 g) frozen pierogisee Recipe
1tbsp.chopped chives, for garnishtips & tricks
CHEDDAR CHEESE SAUCE
1 1/2cupsBéchamel sauce (*see Footnote)see Recipe
1/4tsp.mild paprika
1/4tsp.dry mustard
3/4cupsharp yellow Cheddar cheese, grated
3/4cupsharp white Cheddar cheese, grated
Directions
In a medium skillet, add chopped bacon and turn the heat to medium-low.
Cook until brown and slightly crispy, about 10 minutes. Using a slotted spoon, transfer to a bowl and set aside.
In the same skillet, add butter to the bacon fat and when sizzling, add sliced onion; season with salt and pepper. Stir until nicely coated with fat and sauté the onions for 15 minutes, stirring often.
Meanwhile make the Béchamel sauce and process according to the recipe.
Using a slotted spoon and letting the excess fat drip off, transfer the onion slices to a bowl; set aside.
Preheat oven to 375ºF and lightly grease a 9x9 baking dish with cooking spray; set aside
Back to the sauce… Add paprika and dry mustard; whisk until well blended.
Add cheese, a little at a time, whisking well between each addition.
To assemble the casserole… Place half the frozen pierogies in the prepared casserole; season with salt and pepper.
Add half of caramelized onions and cooked bacon before spooning on half of the sauce; repeat the same steps with the remaining ingredients.
Cover with foil that has been lightly greased with cooking spray and transfer to the preheated oven. Bake for 45 minutes or until the internal temperature of the pierogies reaches 165ºF.
Carefully remove from the heat and let it rest, covered, for 5 minutes.
Sprinkle on chopped chives and serving immediately.
Notes
Footnote: The ingredients are the same but omit nutmeg and salt.