Add quinoa (or oats) and chia seeds to the blender, and blend on high until you have the texture of a fine flour. Add the milk, yogurt, mango, and all remaining ingredients except the sweetener. At this point, I give everything a little stir so the dry ingredients don’t poof up all over the blender. Blend on high until the mixture is smooth, scraping down the sides and blending again, as necessary. It is helpful to stir down to the bottom to make sure everything has been mixed in. Taste and sweeten to your liking. Blend again to distribute.