Simple Chicken Casserole

Ingredients

• 1 tablespoon olive oil
• 1 leek, washed and sliced
• 200g chicken breast fillets, chopped
• 1 tablespoon flour
• 2 potatoes, peeled and chopped
• 1 large kumera (orange sweet potato), peeled and chopped
• 1 small parsnip, peeled and chopped
• 100g green beans, chopped
• 2 teaspoons chopped rosemary
• 2-1/2 teaspoons VEGEMITE
• 1 cup boiling water
• 1 corn cob, cut into wheels and steamed, for serving