Warm stock and drippings in a saucepan.
Sauté chopped veggies in 1/2 cup (1 stick) of melted unsalted butter( or combination of butter/drippings-1/ 4 c. each) until slightly brown.
Sprinkle Wondra flour over veggies and stir frequently until roux obtains a golden color.
Gradually whisk in stock, stirring constantly. Add herb sprigs and bay leaf.(*See note) Bring to a boil then reduce heat. Simmer for about 15-20 minutes.
Strain off veggies and fresh herbs.
Return to low heat and season with salt, pepper, worcestershire sauce and bouillon, if using.
Blend in heavy cream and adjust seasoning further, if needed.
Refrigerate any leftovers promptly Use within 3 days or freeze for up to 3 months.