Potato Bake | Australian Onions

Ingredients

• 2 large brown onions, peeled, halved, thinly sliced
• 2 tbsp olive oil
• 1 tbsp brown sugar
• 1 1/2 kg medium red skin potatoes, quartered, skin on
• 50 g butter
• 2 tbsp plain flour
• 1 ¼ cups cups full cream milk
• 1 cup chicken stock
• 1 tsp Dijon mustard
• 1 cup grated tasty cheddar cheese
• 2 tsp fresh thyme leaves