Mix together 2 Tbs. each olive oil, sweet mustard, and dill. Brush the mixture on the salmon fillets; season with salt and pepper. Preheat oven to 350 degrees, brush a baking sheet with some melted butter. Unroll the phyllo dough and lay a sheet flat on a work surface. Brush the sheet with melted butter, then dust with some caraway and dill. Repeat with 2 more sheets of phyllo, stacking on top of each other.

With a sharp knife or pizza cutter, remove 4-inches off the side of the sheets to form a square. Now, cut criss-cross to make 4 even squares. Transfer the squares to the baking sheet. Lay a piece of salmon in the center of each square and fold up the corners. As you work, keep the phyllo covered with a damp, not wet, towel to prevent drying out. Brush the pastry lightly with butter and bake for 25 minutes or until the fish is opaque. In the meantime prepare potatoes as a side dish.