Add oil to the pan over medium heat. Add onion and saute for 1-2 minutes.

Add mushrooms, saute until mushroom are browned.

Add sherry and cook until it almost evaporates. Stir in chicken stock and simmer until reduced to 1 cup, 10 m

Combine flour and 1/3 c of cooked chicken stock and still until become smooth.

Add flour mixture to pan; return to boil then reduce heat and simmer for 2 minutes until lightly thickened.

Remove from heat and still in butter and salt & pepper

Pour the sauce on top of the french fries

Serve it hot and enjoy