Begin by adding the diced mango, coconut milk, Greek yogurt, sliced banana, honey (or agave), and vanilla extract into a blender.
Next, incorporate the ice cubes and, if using, the chia seeds into the blender.
Blend on high speed until all ingredients are velvety smooth and creamy. Pause to scrape down the sides of the blender as necessary to ensure thorough mixing.
After blending, taste your smoothie. If you prefer a sweeter flavor, incrementally add more honey or agave syrup and blend briefly again to combine.
When the smoothie has achieved your desired consistency and sweetness, pour it into tall glasses.
Notes
Serve immediately for the best flavor and texture. Garnish with fresh mango, chia seeds, or mint leaves.