Potato caramelized onion and cheese galette - Aceline

Ingredients

• 200g salted butter (Benna)
• 400g plain flour (Lamb brand)
• Pinch salt
• Cold water to bind
• 2 medium onions, sliced
• 1 knob butter (Benna)
• 1 tbsp olive oil (Borges)
• 1 tbsp brown sugar
• 1 tbsp balsamic vinegar
• 2 large potatoes, very thinly sliced
• 3 tbsp melted butter
• 1 tbsp chopped fresh thyme
• Salt and pepper
• 100g grated Cheddar
• 50g grated Parmesan
• 2 fresh white ġbejniet, chopped (Benna)