- 1/4 cup buttermilk or fat-free plain yogurt
- 2 tablespoons low-fat mayonnaise
- 1/4 cup blue cheese
- 2 tablespoons fresh chives or scallion greens, chopped
- 4 plum tomatoes, sliced
- 1 small red onion, sliced
- 3/4 pound lean roast beef, sliced
- Lettuce leaves
- 4 onion sandwich buns
- In a small bowl, combine the buttermilk or yogurt, mayonnaise, blue cheese, and chives or scallion greens.
- Coat a large nonstick skillet with nonstick spray. Set over medium-high heat until hot. Place the tomatoes and onion in the skillet. Cook for 2 to 3 minutes per side, or until lightly charred.
- Layer the roast beef, onion, tomatoes, and lettuce on the bottoms of the buns. Drizzle with the blue cheese dressing. Cover with the bun tops.