In 2 quart sauce pan place 3 Tbsp butter and sliced onions
Cook at low to medium heat stirring frequently until onions are translucent
Add chicken broth, salt, pepper, and stir until completely heated through.
Create your white sauce, by mixing butter and flour, then gradually add milk. add salt
Add shredded cheese to white sauce. This sauce should be thick.
Add white sauce to your chicken broth mixture. Let simmer for about 30 minutes.
Serve and garnish with additionally cheddar cheese.