Coarsely chop bell peppers and tomatoes.
In a pan boil 2 cups water. Add bell peppers and tomatoes, cover and boil for about 7 minutes.
Make a puree in a mixer when it is reaches room temperature.
Strain the puree.
In a pan melt butter, add cheese, milk, puree, salt, pepper and let cook on medium flame till the chesse is melted and the soup is bubbling.
Serve hot.