Step 1: Preheat your oven to 325°F (165°C) and prepare a water bath by placing four 6-ounce ramekins inside a large baking dish.
Step 2: In a small skillet, melt the butter over medium heat. Sauté the minced shallots until soft and translucent, about 3 minutes.
Step 3: Add the dry sherry to the skillet and let it simmer until the liquid is reduced by half. Remove from heat and set aside to cool slightly.
Step 4: In a large mixing bowl, whisk together the egg yolks, heavy cream, salt, white pepper, and garlic powder until smooth.
Step 5: Stir the cooled shallot mixture into the cream base, then gently fold in the lump crab meat, being careful not to break up the lumps too much.
Step 6: Divide the mixture evenly among the ramekins. Fill the outer baking dish with hot water until it reaches halfway up the sides of the ramekins.
Step 7: Bake for 30-35 minutes, or until the custard is set but still has a slight jiggle in the center. Remove from the water bath and let cool completely at room temperature, then chill in the refrigerator for at least 2 hours.
Step 8: Just before serving, sprinkle the top of each custard with a thin, even layer of grated Parmesan cheese. Use a kitchen torch to melt and brown the cheese until it forms a crisp crust. Garnish with fresh chives and serve immediately.