Antipasto Salad

INGREDIENTS

• 6 tablespoons extra-virgin olive oil
• 1/2 teaspoon salt
• 1 small garlic clove, minced
• 1 medium red onion, halved lengthwise and thinly sliced crosswise
• 1/2 lb cherry tomatoes, halved
• 1 cup loosely packed fresh flat-leaf parsley leaves
• 1 cup drained bottled peperoncini (5 ounces)
• 1/2 teaspoon sugar
• 3 tablespoons red-wine vinegar
• 2 (6-oz) jars marinated artichoke hearts, drained
• 2 cups water
• 2 tablespoons sugar
• 1 cup assorted brine-cured olives
• 2 hearts of romaine (12 ounces total), torn into bite-size pieces
• 1 (8-oz) jar roasted red peppers, rinsed, drained, and cut lengthwise into 1/4-inch-thick strips
• 1/8 teaspoon black pepper
• 1 teaspoon salt