- 1/3 cup cider vinegar
- 2 teaspoons granulated sugar
- 1 small red onion, thinly sliced
- 1 1/2 tablespoons unsalted butter
- 1 1/2 tablespoons all-purpose flour
- 1/2 teaspoon dry mustard
- 1/2 cup Guinness Extra Stout (without foam)
- 1/3 cup water
- 2 teaspoon packed brown sugar
- 1/2 teaspoon Worcestershire sauce
- 8 large eggs
- 4 thick slices peasant bread (preferably sourdough)
- 1/2 pound extra-sharp white Cheddar, grated
- 1 bunch watercress, coarse stems discarded
- 1/2 tablespoon extra-virgin olive oil
- Bring vinegar, granulated sugar, and 1/2 teaspoon salt to a simmer in a small saucepan. Stir in onion and transfer to a small bowl. Let stand, stirring occasionally.
- Melt butter in a small heavy saucepan over medium heat. Whisk in flour and dry mustard and cook, whisking, 2 minutes. Add beer, water, brown sugar, and Worcestershire sauce and simmer, whisking, until just thickened.
- Fry eggs and toast bread. Reheat sauce, then remove from heat and gradually whisk in cheese until smooth. Season with salt and pepper.
- Top each slice of toast with cheese sauce and 2 fried eggs. Toss watercress with oil, a pinch of salt, and drained pickled onions and arrange on top.