- 1/4 cup unsalted butter, room temperature
- 18 thin diagonal slices ficelle or other narrow baguette
- Fleur de sel (fine French sea salt)
- 1 small bunch watercress, trimmed
- 4 watermelon radishes or other large radishes, very thinly sliced
- Edible flowers or daikon radish sprouts* (optional)
Spread some butter over bread slices. Sprinkle with fleur de sel. Top each bread slice with 2 watercress sprigs. Spread 1 side of each radish slice with butter. Place 2 radish slices atop watercress, buttered side down, overlapping slightly if necessary to fit. Top with flowers or sprouts, if desired. DO AHEAD Can be made 1 hour ahead. Cover; let stand at room temperature.
Watermelon radishes have white skins but are magenta inside; look for them at farmers' markets. Easter Egg radishes (which have a purple, red, or pink skin) or regular radishes can also be used.