To make the crostini, cut the baguette into 20 thin slices and lightly brush each side with oil. Arrange on a baking sheet and slide under the grill for about 2 minutes on each side until golden brown and crisp. Set aside to cool.
To make the smoked salmon pâté, measure the ingredients into a processor, add some freshly ground black pepper and whiz briefly until combined (don’t let it get too smooth).
Spread some pâté on to one half of each cold crostini – so the top of the crostini is half covered with pâté and half plain. Spread a little horseradish on the plain half. Take a square of smoked salmon and twist it into a little rosette. Sit this on top of the horseradish.
Snip a few cress leaves and sprinkle a line between the rosette and the pâté and serve.