Wholegrain mustard

Mustard seed that is only partly ground, in vinegar or wine. The whole seeds give texture and a milder heat than Dijon mustard, because less of the seed is broken. The seed coat holds a mucilage. It acts as an emulsifier, so it helps butter stay in a pan sauce. Add it off the heat. Long boiling makes the heat go and the taste turn bitter. Most brands hold salt, so count it in the salt of the dish.