Big Italian Salad

1 garlic clove, smashed

Salt

2 tablespoons mayonnaise

2 tablespoons red wine vinegar

1/2 teaspoon dried oregano

1/4 cup plus 2 tablespoons extra-virgin olive oil

Freshly ground pepper

1 large romaine heart, chopped

1 small head of radicchio—halved, cored and coarsely chopped

1/4 head of iceberg lettuce, coarsely chopped

1 tender celery rib, thinly sliced

1/2 small red onion, thinly sliced

1/2 cup cherry tomatoes

1/4 cup pitted green olives, preferably Sicilian

8 peperoncini

2 ounces Parmigiano-Reggiano cheese, shaved (1 cup)