Peel and finely chop onion.
Wash and finely chop celery.
Peel and chop potatoes.
Grate cheese.
Slice tomato.
Bring a pan of salted water to boil, add potatoes and cook until soft.
Spray frying pan and heat.
Cook sausages for 3 mins, approx.
Place on chopping board and cut up, divide between 2 serving dishes.
Spray pan and add onion and celery.
Sauté for about 4 mins until tender.
Stir in tinned, chopped tomatoes and bring to boil.
Add sausages.
Reduce to simmer.
Add peas and Worcester sauce.
Simmer for about 5 mins.
Mash sweet potato with butter and half cheese.
Place sausage mixture in serving dishes.
Top with slice of tomato.
Top with sweet potato mix.
Sprinkle over remaining cheese.
Bake for 20 mins.