In a large pot, prepare pasta very al dente, cooking for about half of the time indicated on the package. Drain well and set aside.
In a bowl, combine turkey, ketchup, and onion. Mix well. Add frozen cauliflower and cheese sauce and gently mix. Transfer mixture to a slow cooker.
Add cooked pasta to the slow cooker and gently stir. Cover and cook on high for 3 to 4 hours or on low for 7 to 8 hours, until the turkey is fully cooked.
Add cheese wedges and scallions, and stir until evenly distributed.
If you like, season with salt and pepper, to taste. Dig in!
PER SERVING (1/8th of recipe, about 1 cup): 179 calories, 5.75g fat, 512mg sodium, 19g carbs, 2g fiber, 3.5g sugars, 12.5g protein