Method:
Preheat the oven to 350 degrees fahrenheit. Wash and dry the fresh produce. Trim the sunchokes and peel them; thinly slice about ¼ inch thick. Zest the lemon; cut in half and squeeze the juice into a small bowl. Using your fingers, gently grasp the small, rectangular muscle attached to the side of each scallop and pull it off; discard the side muscle into the trash. Be careful to keep the main part of the scallop intact.
Place the trimmed head of garlic on a piece of foil and season with a drizzle of olive oil and a pinch of salt. Close the foil around the garlic and place directly on the oven rack. Cook for about 45 minutes, or until the gloves are tender and deeply caramelized. Remove from the foil packet and let cool slightly.
Place the sunchokes and heavy cream in a medium pot; season with salt. Cover with a round of parchment paper and bring to a simmer. Add the thyme sprigs and cook for 15 to 20 minutes, stirring occasionally, until the liquid is nearly absorbed and you can see the pan when a spatula stirs the mixture. Remove from the heat and discard the thyme.
Transfer the sunchokes, roasted garlic cloves, and remaining liquid to a blender or food processor, add the butter and half lemon juice and puree until smooth. Taste then season with salt, if desired.
Place scallops on a layer of paper towels and season with salt on all sides; thoroughly pat dry. Let rest in the refrigerator for 15 minutes. Remove and pat dry again. Heat a thin layer of canola oil in a large stainless steel pan over high heat until lightly smoking. Add the scallops, leaving space between each one to prevent excess steaming. Cook scallops without moving them until well browned on the first side, about 1 to 2 minutes. Carefully flip scallops and cook until the second side is browned, about 1 minute longer. Add the remaining lemon juice and cook for 30 seconds or until the liquid is absorbed. Transfer the cooked scallops to a paper towel–lined plate to drain.
Plate the sunchoke puree at the bottom of a shallow bowl. Top with the seared scallops and lemon zest. Garnish with a fresh sorrel leaf, if using.
