Warm Potato Salad with Beer and Mustard Dressing

This is the potato salad I made for the 4th of July party:

Ingredients

Salad:
3 pounds red potatoes
1/2 cup finely chopped red onion
1/4 cup thinly sliced green onions
1/4 cup finely chopped celery
1/4 cup chopped fresh parsley
1/4 cup finely chopped sweet pickles
2 tablespoons beer
2 tablespoons cider vinegar

Dressing:
1/4 cup olive oil, divided
3/4 cup finely chopped yellow onion
3/4 cup beer
1/4 cup cider vinegar
1 teaspoon sugar
3/4 teaspoon salt
1/8 teaspoon freshly ground black pepper
2 tablespoons Dijon mustard

Preparation

To prepare salad, place potatoes in a large saucepan; cover with water. Bring to a boil. Reduce heat, and simmer 25 minutes or until tender. Drain; cool. Cut potatoes into 1/4-inch slices. Combine potatoes, red onion, and next 6 ingredients (through 2 tablespoons vinegar); toss gently.

To prepare dressing, heat 2 tablespoons oil in a small skillet over medium-high heat. Add 3/4 cup yellow onion to pan; sauté 3 minutes or until tender. Add 3/4 cup beer and next 4 ingredients (through pepper); bring to a boil. Cook until reduced to 1/2 cup (about 6 minutes). Place mixture in a food processor. Add mustard to food processor; process until smooth. With processor on, slowly pour remaining 2 tablespoons olive oil through food chute, processing until smooth. Pour dressing over potato mixture; toss gently. Serve immediately.

Yield

8 servings (serving size: 1 1/4 cups)