Small crispy bites with au gratin mushrooms

3 tablespoons of butter

– 1 cup (250 ml) chopped onions

– 2 cups (500 ml) sliced mushrooms

– 1 cup (250 ml) grated mozzarella

– 1/4 cup (65 ml) grated Parmesan
– 1 large  egg
– Oregano
– Salt and pepper to taste
– A slice of baguette bread
Preparation:
Step 1
Preheat oven to 350°F (175°C).