Remove butcher’s twine from lamb; slice through thickest parts of the leg to make one uniform cut. 

In a gallon-sized freezer bag, combine lamb, yogurt, pepper, chili flakes and garlic; refrigerate overnight. When it’s time to grill, heat grill/smoker to 350°F. Place lamb on center rack; season with salt. Depending on thickness of your cut, grill 7 to 9 minutes per side for medium. When the meat is flipped, add asparagus to the grill; cook alongside the meat while it finishes. Remove meat and asparagus at the same time. Dress asparagus with Red Pepper Pesto; season with salt after cooking. 

For the Herbed Yogurt: In a food processor, combine yogurt, parsley, cilantro, oil, onions, garlic, salt and pepper; pulse until chopped and smooth. Spoon yogurt into a dish. 

For the Red Pepper Pesto: In a food processor, combine bell pepper, parsley, cilantro, oil, Parmesan, garlic, lemon juice, salt and pepper; pulse several times, taste for seasoning. 

To serve: Slice lamb against the grain; serve with Herbed Yogurt, Red Pepper Pesto and asparagus.