Place all the ingredients except for the poppy seeds into a blender, blend for 30 seconds. Add the poppy seeds and pulse two times. Store in an air tight container in the refrigerator until ready to use.
For the Salad:
Divide the leafy lettuce blend among 4 plates.
Top each plate with slices of grapefruit, oranges, and avocado. Drizzle with the Creamy Lime Poppy Seed Dressing.