Heat butter in a skillet over medium heat. Add the green pepper and onion and cook until soft.
Add the tomatoes and tomato sauce and cook for one minute. Add all remaining ingredients except the cream. Bring to a simmer, cover and let cook for 20 minutes.
Add the cream and bring back to a simmer. Simmer for 3-5 minutes, until thickened. Remove from heat and serve .
Notes
If the gravy is too thick, add some additional chicken stock until it reaches the desired consistency.
How to thicken red gravy: Simmer for an extra 5-10 minutes if gravy is too thin. If still too thin, mix in a cornstarch slurry (slowly) using 1 tablespoon of cornstarch with 1 tablespoon of water mixed well.
Add additional salt to taste if necessary.
For a spicier gravy, add additional cayenne pepper to taste. Only add ¼ teaspoon at a time as it can be quite hot.
For a richer flavor, use bone broth in place of the chicken stock.
C hop the vegetables finely to get a smoother sauce - you can also puree it if you want it ultra smooth.