Let the Brie sit at room temperature to soften.
In a bowl, mix butter, chives, parsley, Dijon mustard, and grated garlic.
Toss the arugula with lemon juice. Season with salt and pepper.
Spread the herb butter evenly inside the baguette.
Layer the baguette with ham, Brie, and arugula and cover with the top half of the baguette.
In a pitcher, mix the lemon juice, water, and sugar. Stir until the sugar dissolves. Serve over ice if desired.
Enjoy the jambon beurre with chips, a pickle, and lemonade.