Add frozen banana, blueberries, almond butter, flaxseed meal, chia seeds, and almond milk to a high-speed blender and blend on high until creamy and smooth. Protein powder is optional.
If the shake is too thick, add more almond milk. Then taste and adjust flavor as needed, adding more fruit (or a bit of stevia) for sweetness or almond butter for a more nutty flavor and creamy texture.
When serving, an optional step is to pour some coconut or almond milk into the serving glass and then top with the smoothie for a swirl effect.
Garnish with additional chia seeds and/or almond butter (optional) and enjoy! Store mixture in the refrigerator for up to 2 days, though best when fresh.