Preparation time: 24 minutes Prepare the Citrus Vinaigrette by thoroughly combining all ingredients. Makes about 1/3 cup. Prepare the salad: Cut the beef into 1/8" strips; cut each strip in half. Heat oil in a large nonstick skillet over medium high heat. Stir fry beef (1/2 at a time) 1 to 2 minutes. Remove with a slotted spoon; season with salt, if desired. Toss lettuce, beef and oranges in a large bowl. Sprinkle with walnuts and drizzle with the Citrus Vinaigrette. Garnish with strawberries, if desired. Serve immediately. Serving suggestions: Sesame bread sticks.