Heat the oil in a large saucepan
Add the onion and fry for 5 minutes until soft
Add the garlic, pepper and potato
Stir in the flour and cook for one minute
Gradually add the milk and stock, stirring all the time
Add the broccoli and sweetcorn
Bring to the the boil stirring continuously
Reduce heat and simmer for 20 minutes
Stir in about 2/3 of the cheese
Serve the chowder into bowls and top each with a portion of the remaining cheese.