I forgot to take a picture before I started eating last night so, for now, I've used a previous photo of the dish. I'll put up a new one after I eat more.
This cheese sauce is the best I've ever made. I'll detail it last. I first diced an onion and sweated it till golden in an 8x12 pan (or lasagne pan). Then put a layer of thinly sliced ham on the bottom, about a pound or 450gm. Spread the onions over that then put a layer of thinly sliced potato over top. I used 5 small potatoes but any amount is fine. Finally, put a layer of cauliflower over everything.
1/4 cup beef stock
1/4 cup white wine - I had Chardonnay open
4 tbsp butter
2 tbsp flour
1 1/2 - 2 cups milk
1 1/2 - 2 cups grated cheddar cheese - fresh grated tastes best
Melt the butter and flour together and cook the flour taste off for a minute or two on medium+ heat. Don't brown it. Remove from heat and slowly whisk in stock and wine. Whisk in the milk and bring to a boil. Add most of the grated cheddar and stir it in. Sprinkle the remaining cheese over the cauliflower and pour the cheese sauce over everything. Put in the oven at 350ºF for at least an hour and a half. The potatoes take forever to cook this way. I've tried par boiling them but they turn to mush spreading in the pan. Just keep an eye on it and if it's starting to over brown, turn the heat down to 250ºF.
The beef stock and white wine are the secret ingredients here. I usually don't have beef stock available so I use chicken stock but that is clearly a mistake. Cheddar and beef stock are perfect together. Campbell's has a new no salt added stock which is what I used. It's wonderful. The white wine is also a star here. It gave that hint of acidity usually missing in a cheese sauce. Together they sang.