Welsh rarebit

Salad
3 Radishes, trimmed, sliced and lightly salted
8 small pickled Onions
3/4 cup lightly packed inner yellow frisee leaves
3/4 cup lightly packed Arugula (rocket) sprigs
Rarebit
2 slices dense-textured white sandwich bread
2 slices dense-textured brown sandwich bread
1 cup (4 oz) grated good-quality sharp Cheddar cheese
5 tablespoons dark ale
2 tablespoons chilled unsalted Butter, cut into pieces
1 tablespoon Dijon Mustard
1/2 teaspoon Salt, plus Salt to taste
1/4 teaspoon freshly cracked Pepper, plus Pepper to taste
Pinch of cayenne pepper

FOR THE SALAD:
In a small bowl, toss together the Radishes, pickled Onions, frisee and arugula.
FOR THE RAREBIT:
1. Preheat a broiler. Place the bread slices on a baking sheet. Place under the broiler and toast, turning once, until golden brown on both sides, 30-40 seconds on each side. Remove from the broiler.
2. In a small saucepan over medium heat, combine the Cheddar and the dark ale. When the cheese melts, add the Butter, Dijon Mustard, 1/2 teaspoon Salt, 1/4 teaspoon Pepper and the cayenne, and whisk together until evenly melted and combined, 1-2 minutes.
3. Cut each piece of toast in half on the diagonal and arrange around the edges on a flameproof platter. Pour the cheese mixture over the toasts so they are covered completely. Place the platter under the broiler and broil until the cheese bubbles and starts to scorch in places, about 2 minutes. Remove from the broiler.
4. Place the salad in the center of the platter and serve immediately.