- 2 small red onions, cut into 3/4-inch slices
- 2 tablespoons olive oil
- kosher salt and black pepper
- 1 10-ounce merguez sausage
- 1 12-inch ficelle (a thin baguette), sliced in half lengthwise
- 3 tablespoons Dijon mustard
- Heat grill or grill pan to medium-hot. Brush both sides of the onion slices with the oil and sprinkle with ¼ teaspoon salt and ⅛ teaspoon pepper.
- Grill the onions and sausage, turning occasionally, until the onions are soft and the sausage is cooked through, 12 to 15 minutes.
- Slice the sausage into 4-inch pieces. Spread the inside of the bread with the mustard, then form a sandwich with the onions and sausage. Cut in half and serve.