Method

• 1.
  Place zest in a pan with 1 cup (250ml) water. Bring to the boil over high heat, then simmer over low heat for 5 minutes or until zest softens. Strain, reserving zest.
• 2.
  Heat oil in the same pan over medium-low heat. Add eschalots and cook, stirring, for 5 minutes or until softened, then add lemon juice, wine, stock and bay leaf. Simmer for 5-6 minutes until reduced by half. Strain through a fine sieve, pressing down on solids, then return to the pan.
• 3.
  Cook tortellini according to packet instructions, adding asparagus for the last 2 minutes of cooking time, then drain.
• 4.
  Meanwhile, place the sauce over very low heat. Add butter, 1 piece at a time, whisking until you have a thickened and combined sauce. Season well.
• 5.
  Divide tortellini and asparagus among plates, then drizzle with sauce and lemon zest. Serve with the herbs or salad leaves.