Christmas Crostini with Smoked Trout

INGREDIENTS

• 1 pound boneless smoked trout fillets, skins removed
• 4 ounces cream cheese, room temperature
• 4 ounces creme fraiche
• 1/4 cup prepared horseradish
• 1/4 cup freshly squeezed lemon juice (about 2 lemons)
• Freshly ground pepper
• 1 loaf wreath-shaped peasant bread (1 to 1 1/2 pounds)
• Extra-virgin olive oil, for brushing
• 1 bunch watercress, tough stems removed
• 6 ounces cherry tomatoes, halved
• 1 Kirby cucumber, halved lengthwise and thinly sliced crosswise into half-moons