-
1
Preferably, the leftover beef will be from a pot-au-few that has been tenderized by long poaching, but roast beef can work as well.
-
2
It will just need more baking time.
-
3
Make sure the beef is chilled for easy slicing.
-
4
Then, slice as thinly as possible.
-
5
Set aside.
-
6
In a large skillet, melt the butter and lightly saute the onions.
-
7
When golden and very soft, about 10 minutes, sprinkle them with enough flour to make a light roux.
-
8
Stir the mixture thoroughly for 2 to 3 minutes before adding the vinegar and mustard.
-
9
Continue stirring, adding enough stock or Pot-au-Feu broth to make a thin sauce.
-
10
Add the spices.
-
11
Bring the sauce to a boil, then lower heat and simmer for about 30 minutes.
-
12
Assembly: Pour a layer of sauce into a shallow baking dish.
-
13
Layer meat slices, always overlapping, alternating with more of the sauce.
-
14
You should end up with a final layer of sauce.
-
15
Bake, covered, in a 350F (180C) F oven for half an hour, if meat was originally poached, or for an hour, if roast beef.
-
16
Check to make sure sauce does not reduce too much.
-
17
Add more stock if necessary.
-
18
When preliminary cooking is finished, sprinkle surface of dish with a thick coating of fresh bread crumbs.
-
19
Spoon just enough butter over crumbs to moisten them.
-
20
Return to oven for about 30 more minutes, or until a golden crust forms.
-
21
Sprinkle the top with the parsley to garnish, and squeeze over it the juice of half a lemon.
-
22
Serve at once.
-
23
Variations: Add tomatoes, garlic, and/or mushrooms.
-
24
Instead of vinegar, use a little grated horseradish.
-
25
In place of some of the stock, use wine.
