Loin of Lamb en Croute with Shallot/Balsamic Vinegar Sauce

This is a dinner party showstopper: seared lamb loins stuffed with roasted red peppers, crumbled feta, and cooked spinach, wrapped in puff pastry with a decorative braid on top, and served with a silky balsamic shallot butter sauce. It looks far harder to make than it actually is.

The filling combination is what sets this apart from a standard en croute. Feta brings saltiness and tang, roasted peppers add sweetness and color, and the spinach keeps things from getting too rich. Once the lamb is seared and the pastry wrapped, the oven does the heavy lifting.

The sauce is worth the extra steps. Beef stock and balsamic vinegar cook down together until concentrated and intensely flavored, then cold butter gets whisked in piece by piece until the sauce turns glossy and coats a spoon. Roasted shallots fold in at the end and add a deep, caramelized sweetness that plays beautifully against the tangy balsamic.

Pro Tips

• Sear the lamb hard before wrapping so you get a proper crust; the oven time is short and won’t develop the same browning
• Make sure your cooked spinach is very well drained and squeezed dry before it goes onto the pastry — any extra moisture will make the bottom soggy
• Add the butter to the sauce one piece at a time, whisking each piece fully before adding the next; rushing this step breaks the sauce
• Let the wrapped lamb rest 5 minutes before cutting so the pastry doesn’t shatter

Variations

• Swap feta for goat cheese for a creamier, milder filling
• Use veal stock instead of beef stock in the sauce for a more refined, lighter flavor