Southwest Salad

Ingredients

• 1/2 teaspoon grated orange zest
• 1/4 cup orange juice
• 1/2 cup canola oil
• 2 tablespoons sugar
• 3 tablespoons red wine vinegar
• 1 tablespoon lemon juice
• 1/4 teaspoon salt
• 3 heads Boston lettuce, torn
• 1 small cucumber, thinly sliced
• 1 medium ripe avocado, peeled and sliced
• 1 small red onion, sliced and separated into rings
• 1 can (11 ounces) mandarin oranges, drained or fresh orange sections