STEP 1:
Rub your lamb with olive oil and salt, then sear its surface in a hot pan on all sides. Remove from heat and let rest.
STEP 2:
To make the crust, add pistachios, sage, rosemary, and salt to a food processor and blend until fine.
STEP 3:
Brush lamb with Dijon mustard and roll in pistachio mix. Bake on a rack at 400°F (204°C). Use a ThermoPro TempSpike Wire Meat Thermometer to help determine when the lamb has reached an internal temperature of 120°F (49°C). Remove from oven and let rest for at least 10 minutes.
STEP 4:
To make the whipped feta, add all the ingredients listed above to a food processor and blend for a few minutes. Add water if needed to reach your desired consistency.