Preheat oven to 450f/230c degrees.
Combine garlic, rosemary, salt & pepper, bread crumbs well. Then drizzle in the olive oil until just moist, and combine. Set to the side.
Salt & pepper each side of the lamb. Drizzle olive oil into a hot pan and sear off quickly, each side of the rack. 1-2 minutes each side.
Let rack cool for a few minutes, then brush each side with the dijon mustard.
Cover the rack in the bread crumb mixture until it is evenly coated.
If rack bone tips are exposed, cover the bones with foil to prevent charring. You can see from my pictures, I didn't need this step as i had meat covering the rack bones.
Place the rack in an oven proof dish, bone side down, meaty side up.
Roast in oven for 15-18 minutes , depending on your degree of doneness you desire. 145f/65c degrees is the ideal doneness for lamb, but prepare to your level of meat happiness.
Once done, remove from oven and allow to rest for 5 - 10 minutes, loosly covered with foil.
When ready to serve carve between the ribs to portion out.