Orange Tossed Salad

2 tablespoons sugar
2 tablespoons minced shallots
3 tablespoons sherry vinegar
2 tablespoons fresh orange juice
1 teaspoon dry mustard
2 teaspoons extravirgin olive oil
1/2 teaspoon salt

3 cups orange sections (about 3 large oranges)
3 cups torn romaine lettuce
3 cups torn red leaf lettuce
3 cups baby spinach leaves
1 cup thinly sliced red onion
1/2 cup (2 ounces) crumbled feta cheese

To prepare vinaigrette, combine first 7 ingredients in a small bowl; stir with a whisk. Set aside.

To prepare salad, combine orange sections, romaine, red leaf lettuce, and spinach in a large bowl. Add onion and cheese. Pour vinaigrette over salad mixture; toss gently to coat.
from Cooking Light.