Wash bell peppers. Cut each top off, twist out the core and scoop out any seeds.
In a bowl, mix tomato sauce with Italian seasoning, kosher salt, and pepper.
Heat skillet over medium heat. Add turkey, sausage and onion. Cook until no longer pink.
Add garlic, 1½ cups tomato sauce mixture and rice. Stir.
Pour chicken broth into slow cooker. Fill each bell pepper with rice mixture. Divide remaining ½ cup tomato sauce over the peppers.
Secure lid and cook on High for 2 hours. Top with shredded cheese and return lid until cheese melts.
Optional: For browned cheese - place oven rack on bottom-most setting and turn oven to broil. Place crockpot on bottom rack under broiler for 2 minutes to brown cheese(optional).
Notes
If you do not have broth, use water in the bottom of the Crock pot.
If using only 2 -4 peppers, crinkle foil loosely and place in between peppers so they stand while cooking.
I like my peppers slightly firm so the recipe states cook for 2 hours. If you want a softer cooked pepper, set the Crock pot cook time longer.
If broiling cooked peppers, be sure to set rack to the bottom setting. Watch carefully so the cheese does not burn.