Instructions:
Preheat the oven to 325°F.
Spread a generous amount of mustard on one side of one piece of toast, then spread one side of the other piece of toast with the sandwich spread.
Layer both pieces of toast with one slice each of the turkey, ham, cheddar and capocollo. Top one half of the sandwich with a portion of the mushroom sauce and top with the other half. Repeat with the remaining ingredients to make 4 sandwiches total.
Dip the whole sandwiches in the herb crêpe batter, just long enough to coat them well. Let the excess batter drain off.
Melt the butter in a large sauté pan over medium heat. Place the battered sandwiches in the pan and cook just until brown on both sides, about 2 minutes per side.
Place the pan in the oven and bake for about 8-10 minutes, until heated completely through.
Remove and serve with vegetable chips.
Mushroom Sauce
Place 4 tablespoons of the butter in a small bowl and knead in the flour, a bit at a time, to form a smooth paste (beurre manié).
Toss together the mushrooms and lemon juice in a small bowl. Melt the remaining 2 tablespoons of butter in a large sauté pan over medium heat, add the shallots, and sauté until translucent and softened (but not colored), about 2 to 3 minutes. Add the mushrooms, and sauté until any liquid they release has evaporated, about 4 minutes.
Add the brandy and simmer for about 1 minute, setting flame to it (flambéing) if desired. Add the white wine to deglaze, stirring with a wooden spoon to loosen any browned bits on the bottom of the pan. Stir in the cream, and bring to a boil over medium-high heat.
Stir in the beurre manié a little at a time until incorporated and the sauce thickens. Toss in the parsley and season with salt and white pepper.
Herb Crêpe Batter
Combine all of the ingredients in a large bowl, mixing until smooth.