Soak porcini mushrooms in water. Wash and clean the mushrooms. Finely chop 1/3 of the mushrooms. Roast the pine nuts in a pan without fat, take them out, put some aside for garnishing.
Wash herbs, shake dry. Put some marjoram aside for garnishing. Drain the porcini well. Heat 2 tablespoons of oil in a pan. Sauté the porcini and chopped mushrooms.
Put whole mushrooms, pine nuts, herbs and 5 tablespoons of oil in a blender and puree. Season with salt and pepper. Remove from the blender, fold in fried mushrooms. Cut baguette pieces in half horizontally and place on the preheated grill with the cut side down.
Grill for about 3 minutes. Spread the pesto on the baguette, sprinkle with cheese and place on the grill again until the cheese has melted. Arrange the baguette and garnish with pine nuts and marjoram.