Ingredients

1. 5 medium ancho chiles, stemmed and seeded
2. 1 tablespoon unsalted butter
3. 1 pound small white onions, trimmed but with the root end left intact, halved lengthwise
4. 4 garlic cloves, coarsely chopped
5. 1 cup turkey or chicken stock or canned low-sodium broth
6. 2 cups heavy cream
7. 1/4 cup tarragon leaves
8. 1 teaspoon salt
9. 1 teaspoon fresh lime juice

Directions

1. Heat a large cast-iron skillet. Add the anchos and toast over moderate heat, pressing down with a spatula, until fragrant and blistered, about 20 seconds per side. Transfer to a plate and let cool, then cut the chiles into 1/2-inch pieces.
2. Melt the butter in a large skillet. Add the onions and garlic, cover and cook over moderate heat, stirring, until the onions are softened, about 5 minutes. Add the stock and cook until reduced by half, 6 to 7 minutes. Add the anchos, cream and tarragon and cook over moderately low heat until the onions and anchos are tender and the cream is thickened, about 10 minutes. Add the salt and lime juice, transfer to a bowl and serve.

Make Ahead

The dish can be refrigerated overnight. Rewarm gently before serving, adding a few tablespoons of water if the cream is too thick.