Remove lamb from fridge and let it come to room temperature. Preheat oven to 400°F.
To a food processor, add pistachios, bread crumbs, parmesan, rosemary and thyme. Process in the food processor until a very coarse sand texture forms.
Add pistachio mixture to a plate, and add 2 tablespoon olive oil. The texture should feel slightly moist.
Rub lamb with 1 teaspoon olive oil and season on all sides with salt and pepper.
Heat a pan on the stove over medium heat - add 1 tablespoon of olive oil.
Once oil is hot, add the rack of lamb, and sear it on all sides, about 4-5 minutes total.
Remove rack of lamb from the pan and place it on a parchment-lined baking sheet.
Using a basting brush, brush the mostarda on the fat-side of the rack of lamb.
Pat pistachio mixture on top of mostarda, ensuring it adheres to the mostarda. Remove any excess pistachio mixture that has fallen onto the parchment paper, or else it will burn when baked.
Roast the lamb on the baking sheet in the oven for 20-25 minutes. I roasted mine for 23 minutes - I like mine on the rarer side.
Remove lamb from the oven - remove it from the baking sheet and let it rest for 10 minutes.
To serve, carve the racks between the bones to cut into chops.