The crab salad can be made ahead, but the avocado and peach layers are best prepared just before serving.
1 pound fresh jumbo lump crabmeat
2 tablespoons lemon zest
1 tablespoon mayonnaise
1 teaspoon Dijon mustard
5 tablespoons fresh lemon juice, divided
1/2 jalapeño pepper, seeded and finely diced
1/4 cup finely diced celery
2 green onions, finely chopped
Kosher salt and freshly ground pepper to taste
5 to 6 medium peaches, unpeeled and coarsely chopped
2 tablespoons honey
3 medium avocados, diced
Pick crabmeat, removing any bits of shell. Whisk together lemon zest, mayonnaise, Dijon mustard and 1 Tbsp. lemon juice. Fold in jalapeño, celery, green onion, and crabmeat, gently, using a rubber spatula. Season with kosher salt and freshly ground pepper to taste.
Stir together peaches and remaining 4 Tbsp. lemon juice. Reserve 3 cups peach mixture. Pulse honey and remaining peach mixture in a food processor until smooth. Season pureed peach mixture with kosher salt and freshly ground pepper to taste.
Spoon 1/4 cup pureed peach mixture onto a chilled plate. Place a 3 1/2-inch round cutter in center of peach mixture on plate. (A clean, empty tuna can with both ends removed can be substituted for a cookie cutter if you don’t have the right size.) Spoon one-sixth of diced avocados and 1/2 cup reserved chopped peach mixture into cutter, packing each layer firmly and sprinkling with kosher salt and freshly ground pepper to taste.
Top with about 1/2 cup crab mixture. Carefully remove cutter from plate. Repeat procedure with remaining pureed peach mixture, avocado, chopped peach mixture, and crab mixture. Arrange desired amount of arugula around each layered salad; serve immediately.