Under 30 Minutes
For the Sandwich
- 1 onion roll, halved
- 1/2 cup mixed greens
- 3 ounces thinly sliced leftover Roast Beef with Caramelized Shallots
- 2 thin slices red onion
- 2 cornichons, (or gherkins), halved lengthwise
For the Spread
- 1 tablespoon reduced-fat mayonnaise
- 1 teaspoon prepared pesto
- 1 teaspoon grainy mustard
- Coarse salt and ground pepper
Make spread: Mix together mayonnaise, pesto, and mustard; season with salt and pepper.
Layer bottom roll half with spread, greens, beef, onion, and cornichons; top with other roll half.