How To Prepare Roasted Bone Marrow With Sweet And Sour Shallots And Buttermilk?

PRODUCT(S):
EU Premium Black Angus Beef Bone Marrow

Preparation Time: 30 mins Cooking Time: 30 mins Serving: 4

Ingredients:
2 EU Premium Black Angus Beef Bone Marrow
185 ml Beef Stock with Red wine (¾ cup)
4 thick slices sourdough, toasted, halved crossways (8 pieces total)
Finely chopped chives, chive batons and chervil, to serve

Sweet and sour shallots
185 ml sherry vinegar (¾ cup)
185 ml white wine vinegar (¾ cup)
2 tbsp caster sugar
2 tbsp light brown sugar
8 golden shallots, finely chopped

Buttermilk purée
250 ml buttermilk
150 ml thickened cream
4 gm agar-agar
¼ tsp xanthan gum

Method:

1. For sweet and sour shallots, bring vinegars, sugars and 1½ tsp salt to the boil in a saucepan, whisking to dissolve sugar. Stir in shallot, reduce to a simmer & cook, stirring occasionally, until reduced to a jammy consistency (20-25 minutes). Cool to room temperature, cover & refrigerate until required.

2. For buttermilk purée, process buttermilk, cream & agar-agar in a high-speed blender for 30 seconds, transfer to a large saucepan, bring to the boil & boil for 1 minute to hydrate agar-agar. Pour into a wide shallow pan & refrigerate until set (1¾-2 hours). Break into smaller pieces, transfer to a blender & process on high speed until smooth. Sprinkle in xanthan gum & ½ tsp salt & blend to combine. Transfer to a squeeze bottle or piping bag & refrigerate until required.

3. Preheat a grill to high. Drain marrow bones & pat dry with paper towels. Place cut-side up on a wire rack in a roasting pan, season to taste & grill on a low rack until heated through and the tip of a small knife inserted into marrow for 20 seconds feels hot (6-7 minutes), then grill closer to heat until top of marrow is golden brown (2 minutes).

4. Combine demi-glace & ¼ cup sweet & sour shallots in a small saucepan & bring to the boil. Simmer until reduced by half (4-5 minutes). Brush a little on bone marrow, & scatter bone marrow with finely chopped chives.

5. Spread about 2 tsp sweet & sour shallot on each piece of toast, pipe dots of buttermilk purée on top & scatter with chervil & chive batons & serve with bone marrow.