How to Make It
Combine the mayonnaise, lemon juice, dijon mustard, and a pinch of black pepper in a bowl. Set aside.
Toast the baguette until golden, and brush with melted butter. Let cool. Toss the crab meat with olive oil and dill. Spread the lemon mayo over the toast, and divide the crab mixture evenly among them. Season with more black pepper and lemon juice, if desired. Serve at room temperature.