Step 1
Preheat the barbecue cooking grate and hot plate on medium-high heat. In a large bowl, whisk the vinegar, mustard, garlic, lemon rind and 1 tablespoon lemon juice to blend. Gradually whisk in the oil. Season to taste with salt and pepper. Set aside.
Step 2
Lightly brush the lamb chops with more oil. Season to taste with salt and pepper. Place the lamb on the barbecue cooking grate, close the hood, and cook for 4 minutes, or until well browned on the bottom. Turn the chops over. Close the barbecue and cook for 3 minutes for medium-rare doneness, or until cooked to your liking. Transfer the chops to a plate. Set aside for 5 minutes to rest.
Step 3
Reduce the hot plate heat (see note) to medium. Cook the butter on the hot plate until foaming. Add the asparagus and both types of peas. Season with salt. Cook, turning the vegetables often with a flat metal spatula, for 4-5 minutes, or until the vegetables are tender-crisp.
Step 4
Transfer the vegetables to a large bowl. Add the mint and 60ml (1/4 cup) of the vinaigrette and toss to coat. Place the vegetables on a platter. Top with the lamb and serve with the remaining vinaigrette.