Mexican Stuffed Peppers

6 large bell peppers, any color or a mixture1 cup brown rice medley (such as Trader Joe's)1 teaspoon butter1#189;-2 pounds ground sirloin 1 small onion2 envelopes (1.5 ounces each) taco seasoning mix8 ounces tomato sauce1 can (28 ounces) diced tomatoes with liquid 1-2 cups sharp cheddar cheese, shreddedHeat oven to 350 degrees.Halve peppers lengthwise and remove seeds, membranes and stem ends. Immerse in boiling water for 5 minutes. Invert on towel to drain. Lay peppers in a 13-by-9-inch baking dish.Bring 2#189;cups water to a boil. Add the butter and brown rice medley. Bring back to boil and simmer, covered for 35 minutes. Remove from stove. Let rest, covered, for 10 minutes. (Makes about 3#189; cups.)In large skillet cook meat and onion until meat is brown; stir in taco seasoning, tomato sauce and diced tomatoes until well combine then stir in rice medley. Spoon equal amounts of mixture into each hollowed pepper. Cover baking dish with aluminum foil and bake 1 hour.Remove from oven and top each pepper with shredded cheddar cheese. Cover with foil and let sit for 5 minutes to melt the cheese.Serves six.