Preheat the oven to 425°F. Line a large baking sheet with parchment paper.
Preparing the Mushrooms:
Start by cleaning the mushrooms. Use a wet paper towel or soft bristle brush to clean off any dirt and debris from the mushrooms.
Dice the mushrooms – stems and caps – and place into a dry frying pan (no butter or oil).
Preheat the pan over medium heat, add the water, and bring the water to a simmer.
Chanterelles cannot be consumed raw and must be cooked properly! Cook the mushrooms over medium heat until all the liquids evaporate, for about 8 minutes.
Once the mushrooms are dry, add butter and shallots. Stir and cook for a few minutes until the shallots are tender.
Add minced garlic and season with salt and pepper. Cook for a few minutes more, then add the port (or broth) to deglaze the pan.
Pour in the cream (or half-and-half) last. Cook for a minute or two, just until the mixture is thickened, then remove from the heat and cool the mushroom mixture.
Making the Filling:
Grate the cheese into a large mixing bowl. To the cheese, add mayonnaise, fresh dill, and fresh parsley.
Once the mushroom mixture has cooled slightly, add it to the bowl. Use a spatula and mix everything together thoroughly.
If you are not making the appetizer right away, you can cover and store the topping in the refrigerator until ready to use.
Making the Crostini:
Slice the baguette thinly, on the diagonal, (about 1/3-inch-thick slices) for more space for the topping.
Using a small spatula or spoon, add a generous amount of mushroom topping onto each slice of baguette. Place the crostini onto the prepared baking sheet.
Baking Instructions:
Bake the mushroom crostini at 425°F for about 15 minutes, until the edges of the baguette are golden-brown and the cheese is melted.
The filling will be very hot after baking! Allow the crostini to cool for a few minutes before moving.
Transfer the appetizers onto a serving tray and garnish with additional fresh herbs. Enjoy the crostini warm.