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
Preheat oven to 375 degrees. In a food processor, pulse the trout fillets until broken up into small pieces. In a medium bowl, whisk together the cream cheese, creme fraiche, horseradish, and lemon juice. Fold processed trout into cream-cheese mixture, and season with pepper.
Using a long serrated knife, trim off top of loaf to make level. Cut bread vertically into 3/4-inch-thick slices, keeping loaf intact. Brush the top of the loaf with oil. Transfer loaf to a baking sheet, and toast in oven until golden brown, about 12 minutes. Let cool.
Transfer loaf, keeping shape intact, to a round serving platter or cake stand. Gently spread trout mixture over loaf (so it rests atop slices). Arrange watercress, alternating with groupings of the cherry tomato halves and cucumber slices on top, and serve immediately.
Wreath-shaped loaves of peasant bread can be found in artisanal bakeries and gourmet food shops. If you can't find one, simply cut out the center of a round loaf.