Cheesy Potato and Sausage Casserole

Ingredients

• 1 tbsp olive oil
• 1 medium brown onion, peeled and finely diced
• 1 clove garlic, minced
• 6 Wursthaus Beef and Tomato Sausages, chopped
• 1 tin red kidney beans, drained
• 1 red chilli, seeds removed, finely sliced
• 500g potatoes, peeled and cubed
• 3 tbsp butter, divided
• 2 tbsp plain flour
• 1 ¼ cups milk, divided
• ½ cup grated cheddar cheese
• ½ cup grated parmesan