Combine all dressing ingredients (apart from the poppy seeds) in a blender and blend until smooth and creamy. Add the poppy seeds and pulse two times to incorporate.
Divide the baby spinach and kale salad blend between two large bowls.
Top each bowl with half of the avocado slices, blueberries, almonds, feta cheese, and 2 tbsp. of lemon poppy seed dressing.
Notes
Dressing can be stored in an airtight container in the fridge for up to 2 weeks.