This soup brings out the natural sweetness of the carrots.
Peel the carrots, and cut 1 carrot into very thin rounds; reserve for garnish. Cut the rest of the carrots into 1/2-inch pieces.
Melt 2 Tbsp. of the butter in a medium saucepan over medium heat. Add the onion, and cook, stirring occasionally, until soft (about 10 minutes). Add the thyme sprigs, jalapeño, sesame, and 1/2-inch cut carrots. Cook for 10 more minutes, stirring occasionally, and then add the stock and kosher salt to taste. Bring to a boil; reduce the heat, and simmer until the carrots are very tender (about 15 minutes). Remove from the heat, and remove the thyme sprigs.
Puree the carrot mixture in a blender. Pour the soup back in saucepan, stir in the 1/2 cup yogurt, adjust seasoning with salt, and place the lid on the pan.
Melt the remaining 2 Tbsp. butter in a small sauté pan over medium-high heat, and cook until the solids begin to brown. Add the pecans. Toss and toast for about 1 minute. Remove from the heat, and add the vinegar.
Serve the soup in bowls. Dollop each serving with the remaining yogurt and the pecan brown butter. Sprinkle with the carrot coins and carrot tops, and finish with a drizzle of maple syrup.
The Broad Fork