Preheat the oven to 350 degrees f.

In a large stock pot of boiling water, parboil the peppers until tender, just 3 minutes. Remove and let dry on paper towels.

In a large skillet over medium-high heat, add the meat, onions, celery, and seasonings. Cook until the meat is browned, stirring to break up the lumps (drain grease).

Add the precooked rice and marinara sauce and stir well. Remove from the heat and adjust the seasoning, to taste.

Pour enough water into a baking dish to just cover the bottom, about 1/8-inch deep.

Stuff the bell peppers evenly with the rice mixture and place in the baking dish

Bake until the peppers are very tender and the filling is heated through, 20-25 minutes.

Sprinkle each with 1 Tbsp shredded cheese (optional) and broil for 5 additional minutes.