For your tea sandwiches, balance flavors and textures by partnering spreads and fillings of contrasting tastes like we did here with smoked duck and chutney butter.
In the bowl of a food processor fitted with the plastic blade, combine butter and chutney; pulse until well combined.
Thinly spread chutney butter on two bread slices. Cover one with thin layers of duck and watercress; top with other bread slice. Use a serrated knife to trim crusts and cut into two triangles. Repeat with remaining ingredients. Cover with damp paper towels until ready to serve.