Spray the bottom of a crockpot with cooking spray. Dice bell pepper and onion.
Add ground turkey, oregano, bell pepper, onion, egg, bread crumbs, tomato juice, salt, and pepper to a large bowl; mix until well combined. (Using your hands is messy, but usually works the best!) Shape into a loaf and add to the crockpot.
Cover and cook on low for 5-6 hours. When meatloaf has 30 minutes left, add ketchup to the top, then replace the lid and continue to cook.
Meanwhile, prepare the salad: mince parsley and onion, dice avocado and cucumber, halve cherry tomatoes, and chop apples; add all to a large, sealable container, along with the olive oil, rice vinegar, feta, and pepper to taste. Toss to coat evenly, then seal and refrigerate until ready to serve.
Allow meatloaf to cool slightly before cutting; serve with salad on the side. (Serving size: 4 ounce slice of meatloaf, 3/4 cup salad)