Crockpot Pepper Steak

2 tablespoons olive oil
3 pounds beef sirloin, sliced into strips
1 tablespoon minced garlic
1 onion, chopped
1/2 cup soy sauce
1 teaspoon salt
1/2 teaspoon ground black pepper
2 teaspoons splenda
3 green bell peppers, cut into strips
1 tablespoon cornstarch
1/4 cup cold water


Heat the oil in a large skillet over medium heat. Add the steak strips, and quickly brown on both sides, adding the garlic to the steak while it cooks. Transfer the steak and its juices to a slow cooker. Add the onion, soy sauce, salt, pepper and splenda. Cover, and cook on Low for 6 to 8 hours, until the meat is fork tender.
One hour before the end of the cooking time, add the green peppers. Stir together the cornstarch and cold water. Pour into the slow cooker during the last few minutes, and cook until the sauce has thickened.