Preparation Simmer crème fraîche with mushrooms, shallot, garlic, and 1/4 teaspoon each of salt and pepper in a heavy medium saucepan, uncovered, stirring occasionally, until mushrooms are tender and sauce is thickened, about 10 minutes. Reduce heat to low, then add snails, herbs, and butter and cook, stirring, until snails are heated through and butter is incorporated, 1 to 2 minutes. Season with salt and pepper. Serve in small ramekins.
Preparation Simmer crème fraîche with mushrooms, shallot, garlic, and 1/4 teaspoon each of salt and pepper in a heavy medium saucepan, uncovered, stirring occasionally, until mushrooms are tender and sauce is thickened, about 10 minutes. Reduce heat to low, then add snails, herbs, and butter and cook, stirring, until snails are heated through and butter is incorporated, 1 to 2 minutes. Season with salt and pepper. Serve in small ramekins.