Heat oven to 350°F.
Peel shallots, drizzle with oil and wrap in foil. Peel ginger and cut into thin slices. Arrange in a single layer, drizzle with oil, and wrap in foil. Pull the outer paper off garlic. Cut the tips off the heads of garlic so cloves are partially exposed. Drizzle with oil, and wrap each head of garlic in foil. Place all foil packets on a baking sheet. Bake for 15 minutes. Remove ginger (it should be soft), increase temperature to 400°F, and roast shallots and garlic for another 30 minutes until golden brown. When cooled, squeeze garlic cloves.
Soak chilis: While the aromatics are roasting, pour boiling water over the chili peppers to rehydrate them. Let them soak for 15 minutes. Drain water.
Put all ingredients in food processor. Pulse or puree until yellow curry paste reaches your desired consistency. Paste keeps for about a week in the fridge or freeze.
Makes 2 cups.
Approximate Nutrient Analysis per teaspoon serving (based on 8 tablespoons of drizzled oil):
20 calories, 1.5 g fat, 0 g saturated fat, 0 mg cholesterol, 150 mg sodium, 1 g carbohydrate, 0 g fiber, 0 g sugar, 0 g protein