Place quinoa and amaranth in fine sieve and rinse under cold running water for about 10 seconds. Place into medium saucepan.
Cut 3 apples and the quince into quarters, then cut diagonally to carefully remove core from each of the quarter pieces. Cut each quarter in half lengthwise, then slice thinly crosswise into small pieces. Place in pan with grains.
Add cinnamon, cloves, salt, and 3 cups water to saucepan and bring to a boil, then reduce to medium heat for 20 minutes. Remove from heat, then remove cinnamon and cloves, and allow mixture to cool slightly for 5 minutes while you prepare the rest of the ingredients.
Using microplane, remove all the zest from both the orange and the lemon, being careful not to remove any of the white pith, which is bitter. Add zest to blender.
Cut lemon and orange in half and using citrus reamer to extract juice from both, then add fresh juice to blender. Add brown sugar, vanilla, remaining cup of water, and cooked grain-fruit mixture to the blender as well. Cover with a towel and blend on high for 45-60 seconds until the mixture is smooth and uniform.
Divide the warm drink among 2 mugs and serve warm.
*Note it can also be stored in fridge to be served later, warm or cold.