Lamb Loin Roll with Salsify and Sweet Potato

Lamb Loin Roll

• 30 g olive oil
• 10 g Dijon mustard
• 1 garlic clove
• 1 sprig fresh thyme, leaves only
• 1 sprig fresh rosemary, leaves only
• ¼ tsp ground black pepper
• 1 ¾ tsp fine sea salt
• 4 lamb loins, boneless (approx. 120 g each)
• 500 g water
• 500 g sweet potatoes, diced (3 cm)
• 500 g black salsify, peeled, cut in pieces (3 cm) (see tip)
• 4 slices white sandwich bread (approx. 200 g)

Sauce and Finalisation

• 40 g unsalted butter, soft
• 40 g plain flour
• 50 g cream
• 50 g milk
• 1 meat stock cube (for 0.5 l), crumbled
  ou 1 heaped tsp meat stock paste, homemade
• ¼ tsp fine sea salt
• ¼ tsp ground black pepper
• oil, for frying
• 2 sprigs fresh thyme, for garnishing (optionnel)