These individual beef encroûtés are a dinner party show stopper! Ingredients (for 6) 1 kilo of trimmed filet of beef 2 tablespoons of Dijon mustard 2 egg yolks Ready made puff pastry 1 kilo of firm white mushrooms 1 large onion, finely diced Knob of butter Sea salt & freshly ground black pepper Start by making ….