Beef stroganoff - Recipe - Marché Adonis

Ingredients

• 1 onion, chopped
• 1/2 cup fresh mushrooms, sliced
• 1 tbsp mustard
• 2 tbsp soya sauce
• 450 ml cooking cream
• 1 cup beef broth
• 1 kg beef tenderloin strips
• 2 tbsp unsalted butter
• Salt and pepper