Horseradish Mustard. Horseradish Mustard. Horseradish Mustard. A wholegrain mustard with a spicy horseradish kick. £2.30 Quantity: at £2.30 each Add To Basket Wholegrain mustard made with yellow & black mustard seeds and fresh grated horseradish from or garden or from friends gardens whenever possible. Solves the problem of what to have with the roast beef. Ingredients: Water, Mustard Seeds (26%), Cider Vinegar, Agave Syrup, Horseradish (7.5%), Chilli flakes. Allergen information: Allergens listed above in bold. Suitable for Vegans & Gluten free diets. Minimum net weight 110g.