Remove tail and claw meat from lobster, reserving all shells. Poach lobster meat in simmering salted water for 6 minutes, then remove from water and allow to rest. Once cool, remove meat and chop to a small dice. Reserve.
Heat olive oil in a medium-size pot over medium heat, and roast lobster shells for 4 minutes. Once roasted, cover shells with bacon and duck fat and reduce heat to low. Peel potatoes and cut a cylinder from each, reserving potato scraps in cold water. Cut cylinders into 1 inch-thick discs. Add potato discs to fat and poach until fork-tender.
Place potato scraps in a small saucepot, cover with water and season with kosher salt. Bring to a simmer and cook until tender, then pass through a food mill. Add 2 tablespoons of poaching fat to mashed potatoes, stir in lobster chunks and season to taste.
Place warm potato disc in center of each plate. Make quenelle of lobster-potato mash and place on center of disc. Garnish with lobster tentacle, smoked salt and micro celery.
Note: Olive oil can be substituted for bacon or duck fat if absolutely necessary, but substitutions are not recommended.