Perfect Potato gratin with Feta cheese - My Greek Dish

Ingredients

• 1.5 kg potatoes, peeled and thinly sliced (53 ounces)
• 2 cloves of garlic, finely chopped
• 2 red onions, chopped
• a pinch of oregano
• 1 tbsp honey
• 2 tbsps butter
• 2 tbsps flour
• 1 cup vegetable stock
• 1 cup heavy cream
• 150g feta cheese (5-6 ounces)
• a handful chopped spring onion
• salt and freshly ground pepper
• a handful of Parmesan cheese, grated
• 4 rashers bacon, chopped (optional)