Using 1 tablespoon butter, brown the onion in a medium pan over medium heat until translucent.

Add the garlic and cook for another minute.

In a slow-cooker, add the beef broth, corned beef, sauerkraut, seeds, onions, garlic, and remaining butter.

(Feel free to put the seeds in a tea ball if you don't want to eat them in the soup later.

They all soften nicely though.) Cook on Low for 7 hours or High for 3.5 hours.

Serve topped with cheese crisps and thousand island as desired.