Wash peppers and cut out core and seeds by cutting a hole in the top of the pepper. (See picture above)
In a medium large skillet over medium heat, add a drizzle of olive oil and chopped onions. Season with a pinch of salt and pepper. Cook until onions have softened, about 4-5 minutes.
Add sausage to the pan and break up large chunks to ensure even cooking. Cook until the sausage is browned and cooked through.
Drain off excess grease
Add in tomato paste, tomato sauce, and garlic, salt and pepper.
Add in couscous and stir to combine
Slowly add one cup of water and stir until combined. Cover and cook 5 minutes or until couscous is tender. Remove from heat and stir to fluff the couscous.
Drizzle a little oil over the bell peppers and season with salt and pepper. Place in crockpot.
Fill each pepper with meat mixture. Place excess filling in crockpot if desired.
Slowly pour about 1 cup of water in the bottom of of the crockpot to help create steam.
Cover and cook on low for 6-8 hours or until peppers are desired tenderness
About 5 minutes before serving, place 1-2 Tbsps of cheese on each pepper and re-cover until melted.