lamb with carrot demi and leek marrow

It’s been a while since I cooked a meal for the blog, so when a leg of lamb arrived at my doorstep (care of the lovely folks at the American Lamb board), I took that as a sign that I should get my ass in the kitchen.  I’ve been on a carrot kick all spring, and I’ve made several variations of the caramelized carrot soup from Modernist Cuisine.  It occurred to me that the deep, sweet flavor of pressure-cooked carrots is not too dissimilar from that of a beef demi-glace (the thick, rich sauce that restaurants often serve over red meat).  This is undoubtedly the quickest demi-glace you’ll ever make, and I’ve gotta say, it’s fucking amazing. Vegetarians will throw a parade in my honor.

Thinking about demi-glace also got me in the mood for bone marrow.  I’ve seen a few faux marrow preparations in the past and I always find them amusing.  However, a big part of the appeal of roasted bone marrow is its decadent, gelatinous texture.  For my version, I decided to use a section of leek as a fake bone and achieve a convincing marrow texture by pressure cooking leek and onion, then setting it in a fluid gel.  The result was quite a bit darker than roasted bone marrow, but the richness and texture were spot-on.

For the recipe, keep reading…

Carrot Demi-Glace

  • 200g carrot juice
  • 1g baking soda
  • 50g high-quality soy sauce
  • 2g cornstarch
  1. Combine the carrot juice, baking soda and soy sauce in a small saucepan high heat.  Bring to a boil, stirring frequently.  Reduce the heat to medium and continue simmering the mixture until it turns dark and thickens, about 20 minutes.
  2. In a small bowl, combine the cornstarch and a few teaspoons of the hot carrot mixture.  Stir to combine, then add to the rest of the carrot mixture.  Cook 3 minutes more to thicken.  Note that the sauce will also thicken as it cools.

Leek “Marrow”

  • 1 medium leek
  • 50g chopped white onion
  • .7g baking soda
  • 1 pat butter
  • .5g agar agar
  • .2g xanthan gum
  1. Trim the green end of the leek and save for another use.  Trim and discard the root end.  Cut a 1.5” section from the white end to use as the marrow bone.  Remove the inner rings of the leek from this section, leaving 3-4 of the outer rings in place.
  2. Dice the inner rings of leek, plus other sections of white leek until you have 25g.
  3. Combine the 25g of leek with the white onion, baking soda and butter in a small, nonreactive bowl (stainless steel, glass or ceramic) that will fit easily into your pressure cooker. 
  4. Add water to the pressure cooker, then place the bowl of leek and onion inside, preferably on a rack so the bowl doesn’t touch the bottom of the pot. Attach the lid and pressure regulator and pressure cook for 20 minutes. Remove from heat, vent and allow to cool.
  5. Meanwhile, blanch the in-tact section of leek rings in boiling water for one minute, then chill in an ice bath until ready to serve.
  6. Place the cooked onion and leek mixture over medium-high heat in a small saucepan.  Add the agar agar and xanthan gum and stir to combine.  Allow the gelling agents to fully hydrate by holding a temperature of at least 83C for 3 minutes, stirring frequently to prevent scorching.  Lower the heat, and season to taste with salt.  Note: if you plan to serve the marrow with additional salt, you may want to undersalt the marrow at this point.
  7. Place the leek bone on a plate and spoon in the leek and onion mixture.  The mixture will firm slightly as it cools.  For a more convincing roasted bone marrow effect, lightly burn the top and sides of the leek with a blowtorch.
  8. To finish, top with flake sea salt and serve with chervil, parsley or celery leaves tossed in a vinaigrette. 

If you chose to omit the lamb and substitute roasted mushrooms, you’d have a pretty exceptional vegetarian dinner on your hands.  However, a pile of charred lamb, cooked sous vide for 48 hours at 56C was the perfect way to mop up that delicious carrot demi.