The key to getting ground turkey to stay moist is to make a panade with bread and milk.
Here's my version (adapted from ATK) and our family loves it. It's a big batch and not exactly throw it all in the slow-cooker but freezes well and worth the effort to brown the meat and soften the onions.
Slow-Cooker Turkey Chili
2 slices bread, torn into 1-in pieces
¼ c whole milk (or soymilk to keep it dairy-free)
2 lb ground turkey
3 T vegetable oil
3c onions, minced
¼ c chili powder
¼ c tomato paste
6 cloves garlic, minced
1 T cumin
1 t oregano (or 1 T fresh oregano if you have it)
½ t red pepper flakes
1 15-oz can tomato sauce
1 15-oz can dark red kidney beans, drained and rinsed
1 15-oz can light red kidney beans, drained and rinsed
1 15-oz can black beans, drained and rinsed
1 28-oz can diced tomatoes, with juice
1½c low-sodium chicken broth or water
3 T soy sauce
1 T brown sugar
2 t canned chipotle chile in adobo sauce, minced
1. Mash bread and milk into paste in a large bowl. Mix in ground turkey and ½ t salt and ½ t pepper.
2. Heat oil in 12-in skillet over medium-high heat. Add onions, chili powder, tomato paste, garlic, cumin, oregano and red pepper flakes. Cook until softened, 8 to 10 minutes.
3. Stir in turkey mixture, 1 pound at a time and cook, breaking up any large pieces, about 3 minutes per pound. Stir in tomato sauce, scraping up any fond. Transfer to slow cooker.
4. Stir beans, diced tomatoes, broth, soy sauce, sugar and chipotles into slow cooker.
5. Cover and cook, 4 to 6 hours on low.