Parmesan and pepper Jack cheeses for topping each pepper
Preheat oven to 350 degrees F.
Cook rice on the stove. Then, measure out 1 1/2 cups for the peppers. Set aside. You will have about half a pot of rice leftover to use in another dish.
Pour all of the red gravy ingredients into a small saucepan. Simmer over low heat for about 20 minutes, stirring occasionally.
Heat a large pot of boiling water on the stove.
When boiling, submerge the peppers into the water in batches of three or four.
Boil until the peppers soften and turn military green, about 10 minutes per batch. Remove each boiled pepper carefully with kitchen tongs. Then, transfer to a colander to drain.
Heat a skillet over medium heat. Then add the butter or oil and chopped onion and celery to the skillet.
When the onion and celery are almost browned, add the ground beef.
When the ground beef is browned, add the minced garlic and cook for 1 additional minute.
Drain the meat and veggies to remove the excess beef fat.
Return the meat and veggies to the skillet. Then, add the 1 1/2 cups of cooked rice and almost all of the red gravy. Stir until well-combined.
Reserve a bit of the tomato gravy to pour into the bottom of the skillet that you will use to bake the peppers.
Use a large spoon to fill each boiled pepper with the stuffing.
Then, top each pepper with Parmesan and pepper Jack cheeses.
Bake for 15 to 20 minutes, or until the peppers are cooked through and the cheese is browned and melty.
Let the peppers rest 5 minutes before serving.
I used garden peppers for this recipe, and most of them were much smaller than the ones available at the grocery store. So while I used 7 peppers, you might only need 4 or 5 store-bought peppers for this recipe. If you have leftover filling, you can let it cool and freeze it for your next beef stuffed bell peppers with tomato sauce batch.