2 cloves of garlic, one finely chopped, one kept whole
1 teaspoon fresh thyme leaves
1 teaspoon Dijon mustard
3 tablespoons crème fraiche
Salt and pepper
Heat up a griddle pan until very hot, then place on your sourdough slices, and cooke for about two minutes per side, so you get nice griddle lines, then set aside
While your sourdough is griddling, in a sautee pan, heat a little oil and then throw in your mushrooms, keep the pan nice and hot, let the mushrooms get some colour on them, this should take 3 or 4 minutes or so, when they're looking golden at the edges, turn the heat down and then add in your chopped garlic and thyme, salt and pepper, and stir, cooking the garlic off but making sure it doesn't colour. After about a minute, throw in your crème fraiche and mustard, and stir to combine, then take off the heat.
So now you're ready to plate up, take your slices of sourdough, and rub your whole garlic clove over the top surface of each griddled slice, it will leave a lovely garlic oil on it. Then simply top each slice with the mushrooms and eat!