Place the halved strawberries, lemon rind and juice, water, honey, salt and cayenne pepper in a medium saucepan over medium-high heat and bring to a simmer. As strawberries begin to release their liquid, soften, and start to break down, reduce heat to medium-low and continue cooking, stirring occasionally, for about 10 minutes or until fruit is very soft. Remove from heat. Pass mixture through a fine mesh strainer.
Make the lamb
Preheat oven to 230 degrees C. Line a shallow baking dish with foil, bringing ends up and over sides of the pan.
Generously season rack of lamb on both sides with kosher salt, freshly ground black pepper and cayenne pepper. Place lamb on prepared pan. Roast rack of lamb in hot oven about 10 minutes to sear. Remove pan from oven. Reduce oven temperature to 190 degrees C.
Preheat oven to 190 degrees C.
Combine mustard and onions in a small bowl. Pour melted butter into bread crumbs in a separate bowl; stir until mixture resembles wet sand. Season with salt.
Coat top of lamb generously with the mustard mixture. Sprinkle crumb mixture onto the mustard mixture and press down to create a crumb crust.
Roast rack about 15 minutes or until it reaches an internal temperature of 50 degrees C. Let rack rest 10 minutes before slicing between ribs into four 2-rib servings or two 4-rib servings.
Mix thinly sliced mint into strawberry sauce just before serving. Spoon a small pool of the sauce onto serving plates. Place ribs on sauce to serve.
One 8-bone rack of lamb is enough for 2 large or 4 smaller portions.