Valencian Salad - Cooking with Kids

Ingredients

• 3 tablespoons olive oil
• 1 tablespoon balsamic vinegar
• 1 tablespoon lemon juice
• ¼ teaspoon salt
• ⅛ teaspoon black pepper
• ¼ sweet onion, cut into ¼-inch pieces
• 1 head Romaine lettuce
• ½ can of corn, drained and rinsed
• 1 tomato, sliced