In a large bowl mix the buckwheat flour, 1/2 teaspoon of salt, 2 tablespoons of melted butter, eggs and milk until smooth. Cover and let it sit in the fridge for at least 30 minutes (it can sit overnight).

Melt 1 tablespoon of butter and 1 tablespoon of vegetable oil in a large frying pan over medium heat. Sauté the mushrooms until brown. Don't crowd the pan so that the mushrooms brown and don't steam. You may need to do this in several batches. Add more oil and butter if the pan gets too dry.

Season the mushrooms with half a teaspoon of salt and 1 teaspoon of fresh thyme.

In clean 10 inch nonstick pan or crêpe pan, use a paper towel to grease the pan with a some of the melted butter lightly.

Pour in 1/4 cup of the batter, swirling the pan to create a thin layer on the bottom of the pan.

Cook until it lifts easily from the pan and flip. Cook both sides until lightly brown but not too mud (or it will get too crispy and won't be pliable). Cook until all the batter is gone (this should yield at least 8 crêpes).

Layer the middle of each pancake with thin slices of the brie, top with about an eighth of the mushrooms, and sprinkle with some more fresh thyme. Fold the sides over to the middle.

Serve with a fresh salad or sliced tomatoes.