If making tomato sauce or stewed tomatoes, reserve the skins. Place them on a dehydrator sheet or parchment-lined baking sheet. Dehydrate at 135F for 8 to 12 hours (or out in the sun)!
Place the tomato skins in a coffee grinder or a blender, and grind until they are a fine powder. Store in a jar for up to 2 months. Use on top of soups, stir-fries and more for a subtle tomato kick.