Preheat the oven to 350 degrees F.
Mix together the crab, mayonnaise, chives, hot sauce, lemon zest and lemon juice in a bowl. Set aside.
Spread 2 slices of the bread with the mascarpone. Sprinkle the Cheddar for the next layer. Top with equal amounts of the crab mixture and scatter the tomatoes over. Top with the cucumbers and Brie. Spread the chutney evenly on the 2 remaining bread slices and close the sandwiches.
Heat the butter in a large nonstick skillet until foaming, about 45 seconds. Place the sandwiches in the pan and toast for about 2 minutes. Flip the sandwiches and place the entire skillet in the oven. Bake until a melting tenderness is reached, about 4 minutes. Garnish with lemon and pepper.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.