Preheat the oven to 400 degrees F (200 degrees C). Place the half slices of baguette on a baking sheet. Bake until lightly toasted, about 6 to 8 minutes, and then cool to room temperature. Arrange the toasted bread on a platter; top each with a thin slice of the pâté. Top the pâté with a tiny spoon of the jelly, a walnut half and a tiny sprig of the rosemary or parsley.