Parsnip Au Gratin

A lower carb substitute for pure Potato Au Gratin
If you have a mandolin, you can get these parsnips uber thin. If not, a regular chopping knife will do. Serve with vegetarian “italian sausages” and ground mustard.
Ingredients
- 3 medium potatoes, sliced thin
- 5 parsnips, sliced thin
- 1/4 white onion, sliced thin
- 1 cup shredded white sharp cheddar cheese, divided
- 1 cup shredded gruyere cheese, divided
- 4 Tbsp salted butter, room temperature
- 3 Tbsp all purpose flour
- 2 tsp salt
- 2 tsp pepper
- 2 cups heavy cream
- 1 tsp nutmeg
- 3 sprigs fresh thyme (optional)
Directions
- Preheat oven to 400F
- Butter a square, glass casserole dish. Layer potatoes and parsnips halfway up casserole dish.
- Add all onions in an even layer. Salt and pepper to taste and add 1 Tbsp butter. Add a layer of 1/4 cup of each cheese. Layer rest of potatoes and parsnips.
- In a medium saucepan, melt remaining butter over medium heat. Add flour, salt, and pepper, stirring constantly. When flour turns yellow, add cream while stirring. Let roux cook until it thickens considerably, stirring occasionally. Add 1/2 cup of each cheese into roux and stir until melted.
- While cheese mixture is hot, pour over potatoes.
- Cover with aluminum foil and place in oven for 1 hour.
- Remove foil and top with remaining cheese and thyme, sprinkle nutmeg.
- Cook for 30 minutes, or until parsnips are tender and top has browned