Use a 6-quart slow cooker. Place the ground turkey in a large skillet and brown until no longer pink. Pour in the jar of pasta sauce (set the unrinsed jar aside for later use).

Ladle a scoop of meat sauce into the bottom of your slow cooker insert, and add a layer of lasagna noodles. You might need to break a few noodles to get a good fit.

Smear the ricotta onto the noodles, and add a handful of shredded cheese. Repeat the layers until you run out of ingredients. Put the hot water into the pasta sauce jar, seal it, and shake. Pour this tomato liquid evenly over the top of the assembled lasagna.

Cover and cook on low for 6-7 hours, or until the noodles are bite-tender and the cheese has fully melted and the top has begun to brown and pull away from the sides.

Uncover and unplug the slow cooker. Let the lasagna sit in the cooling slow cooker for 15 minutes before serving.