M&S Plant Kitchen Gravy Vegan gravy made with vegetable stock and onions, perfect for pouring over a nut roast. Simply heat in a saucepan or in the microwave. Gluten free. Suitable for vegans. M&S Plant Kitchen offers a wide selection of flavour-packed, plant-based products that are totally delicious. Each product is made of 100% plant-based, vegan-friendly ingredients.