Preheat oven to 350 degrees. Brush mushroom caps with half the olive oil and place gill side up in an oven proof dish just large enough to hold in a single layer. Sprinkle with garlic and drizzle with the remaining oil and season with salt and pepper.
Beat together the cheese, sour cream, egg yolks and tarragon with a pinch of salt. Spoon the mixture into mushroom caps. Bale for about 20 minutes until custard is set and bubbly and mushrooms are soft. Sprinkle more chopped tarragon over mushrooms and serve.
Find any recipe, add your own, make grocery lists easily from recipes. Enter any 3 ingredients and BigOven will tell you what you can make. It's free! (4.5/5 stars)