Add the tart cherry juice and almond milk to the blender first so the blades have liquid to grip.
Add the cooked beetroot, frozen banana, Greek yogurt, chia seeds, grated ginger, and spinach if using.
Blend on high for 45 to 60 seconds, stopping once to scrape down the sides, until the mixture looks smooth and the color is even with no beetroot flecks.
Taste and add honey if the smoothie needs more sweetness. Some cherry juices are sweeter than others.
Add the ice cubes and blend again for 15 to 20 seconds until frosty and thick.
Pour into two glasses and serve right away, while it's cold and thick.