Who says meat and potatoes can't happen between two slices of bread? And so it is that thin slices of roast beef rest between peppery arugula and crisp, tangy salt-and-vinegar potato chips. In place of Gruyere, cheddar could be swapped in.
Slice baguette horizontally, and spread both sides with remoulade. Layer one side with remaining ingredients, and top with the other half of baguette.