Mustard Sauce for Poached Fowl or Fish

• 100 g mirepoix
• 3 shallots, finely chopped
• 100 g

Soften the mirepoix and shallots in 50 g of the butter, add the vinegar and white wine, bring to the boil and reduce to one-third of its original volume. Add the stock and further reduce by half. Add the crème fraîche and reduce until the whole has a light, creamy consistency. Whisk the mustards into the sauce and pass it through a fine sieve. Reheat the sauce, adjust the seasoning, add the rem