Wash cucumber and leafy greens and place them in blender with almond milk. Blend until smooth.
Add strawberries, lemon juice and flax and chia seeds (if using). Blend until smooth. Add milk as needed to reach desired consistency.
Notes
Blending the cucumber and greens with the liquid first prevents chunks of greens. This is especially useful if you're trying to hide the greens from a picky eater! Or simply want to avoid the risk of having a chunk of spinach stuck in your teeth!