Step 1: 1. Place the sliced Corned Beef in a oven proof dish.
Step 2: 2. Chuck the onion and carrot in with it
Step 3: 3. Stir the mustard and pepper in with the stock and pour on top
Step 4: 4. Cook in a medium oven until the carrots and onions are cooked
Step 5: 5. Once cooked, remove as much as the solids from the fluid as possible.
Step 6: 6. Pour the liquid into a pan, and heat on the hob, until boiling vigorously.
Step 7: 7. Remove from the heat, and pour in the corn flour, stirring constantly, until smooth.
Step 8: 8. Return to the heat and bring to the boil.
Step 9: 9. Serve the meat, onions and carrots with mashed potato and veg, and pour over the gravy.
Step 11: The corned beef can be frozen, then defrosted and reheated in the microwave.