a picture of tomatoes, until I can get something better
food pic
The secret of the sauce is to use 1/2 cup less liquid than the package of soup calls for. This recipe assumes it is 3 1/2 cups, but check your brand and adjust accordingly.
 By reducing the amount of liquid, and using milk as well as water, you get a deliciously creamy sauce.
If you can't get white onion soup, use leek and potato or any mild white soup.
You can also leave out the curry powder and serve this as a creamy potato casserole.
Creamy Potato Curry
For two to three people, you will need:

1 package white onion soup
1 1/2 cups 2% low-fat milk
1 1/2 cups water
1 410g/15 oz can potatoes
1 200g/7oz can peas
1/4 teaspoon curry powder
1/4 teaspoon cinnamon

Make up the white onion soup using the milk and water. Stir in the curry powder and cinnamon. Open the can of potatoes, drain, and rinse the potatoes. Add to the soup mix. Open the can of peas, drain off the liquid and add the peas to the soup mix. Cook the time indicated on the package.