For the Crepes
5 tablespoons melted unsalted butter, plus more for the skillet
2/3 cup buckwheat flour
1/3 cup all-purpose flour
1 3/4 cups whole milk
3 large eggs
1/2 teaspoon salt
Combine the melted butter, both flours, milk, eggs and salt in a food processor and process until smooth. Let the batter rest at room temperature at least 1 hour or overnight.
Heat a nonstick skillet over medium heat. Lightly butter the skillet, then add 1/3 cup of the batter and quickly swirl to coat the bottom of the pan. Cook until the crepe sets and browns around the edges, about 2 minutes. Carefully lift with a rubber spatula, flip over and cook about 30 more seconds. Transfer to a plate. Repeat until all the batter is used. You can keep the crepes loosely covered in foil, in a 275 degree oven to keep them warm, while you make the hash.
Repeat with the remaining batter, adding more butter as needed and stacking the finished crepes.
For the Hash Filling
2 tablespoons butter
1 clove of garlic, minced
1 medium onion, chopped
1 cup chopped wild mushrooms (baby shiitakes, cremini, hen of the woods)
salt and black pepper
4 cups cooked and cubed sweet potatoes
1 tablespoon fresh thyme leaves, plus more for garnish
Fried eggs, for topping
crumbled goat cheese, for topping
Heat the butter in a saucepan or skillet over medium heat and saute the onion, garlic and mushrooms until soft, about 5 minutes. Season with salt and pepper. Add the sweet potatoes and thyme and mix through. Cook until sweet potatoes are warmed through, about 3 minutes. Serve over crepes and top with goat cheese, fried eggs, and additional thyme leaves.