Preheat the oven to 400ºF. Line a baking sheet with parchment or waxed paper.
In a large mixing bowl, whisk together the dry mustard, sugar, vinegar, yellow mustard, sesame oil, soy sauce, paprika, and cayenne. Mix thoroughly and set aside.
Lay the 3 sheets of phyllo dough, stacked one on top of each other, on a flat surface. Brush the edges of the top sheet of dough with 1 tablespoon of the melted butter. In the center of the top sheet of dough, spread one fourth of the mustard sauce in a circle. Sprinkle with the herbs. Set aside.
Season the cheese and salmon slices with salt and pepper. Wrap the brie with the sliced salmon, allowing the salmon slices to overlap. Place the salmon-wrapped Brie in the center of the mustard-herb circle. Fold two of the ends of phyllo in toward the center off the dough. Fold the remaining ends in, forming a package, and seal it completely. Place it, seam side down, on the baking sheet. Lightly brush the dough with the remaining 2 tablespoons meltedbutter. Bake until golden brown, 6 to 8 minutes. Cool for several minutes before slicing to serve.
Toss the bread slices with the olive oil in a large mixing bowl. Season with salt and pepper. Lay the croutons on a baking sheet and bake until golden brown, 4 to 6 minutes.
Serve the cheese on a platter with the croutons and the remaining mustard sauce.
Yield: about 12 appetizer servings