Basing a sauce on English mustard always makes me think of Stoppard’s Arcadia. Frankly, I’d recommend seeing it regardless of what you do or do not propose to do with the ground seeds of sinapis alba, but in particular I remember Thomasina’s exhortation:
“When you stir your rice pudding, Septimus, the spoonful of jam spreads itself round making red trails like the picture of a meteor in my astronomical atlas. But if you stir backwards, the jam will not come together again.”
This is an extraordinarily round-about way of saying that you can proper fuck up balance with mustard, and you won’t be able to stir it back out again. Too little and it’s mild heat and boredom. Too much, and it’s an acrid horrorshow, like a mouthful of hops and wasabi.
For all that, I love devilled kidneys. My dad used to make them as a breakfast treat, quick and dirty the way he picked up in the army. He’d thicken with breadcrumbs and dump in a bucket of ketchup. The sauce was pulpy and fiery, perfect for the savoury of the offal.
Veguary precludes that a bit, but here’s a fine brunch of spicy mushrooms.