Tuna Salad with Hard-Cooked Eggs, Radishes, and Capers

Ingredients

• 1/4 cup finely chopped onion
• 1/2 cup extra-virgin olive oil
• 3 (5-ounce) cans solid white tuna in water
• 2 hard-cooked eggs, sliced thin
• 1 celery rib, minced
• 2 radishes, trimmed, halved, and sliced thin
• 1/4 cup capers, minced
• 2 teaspoons lemon juice
• 1/2 teaspoon sugar
• 1/2 teaspoon table salt
• 1/2 teaspoon black pepper