Brown onions and zucchini in a large pan with 1 T butter
Once onions are brown, add garlic and saute
Add 3 T butter and ¼ cup flour to start the roux
Add chicken broth, lemon, salt, paper, and mustard
Rinse beans and add them to the pan
Simmer for 5 minutes as sauce thickens
Add spinach
Add milk or cream and cook together for 5 minutes.
Top with parmesan cheese, parsley, and lemon zest
Serve and enjoy!