Complex sentence: In the Middle Ages, almond milk was known in both the Islamic world and Christendom, where its vegetable composition--being a nut that is the seed of a fruit of a plant--made it suitable for consumption during Lent.
Split into simpler sentences: In the Middle Ages, almond milk was known in both the Islamic world and Christendom. Being a nut that is the seed of a fruit of a plant--made it suitable for consumption during Lent.