In a pan, mix the sauerkraut with all the other ingredients up to and including the pepper, cover and simmer for approx. 20 mins. Remove the thyme and bay leaf.
Charcoal/gas/electric grill: Grill the sausages over/on a medium heat (approx. 200 °C for approx. 10 mins. on all sides. Briefly grill the bread (cut side down) alongside.
Mix the mustard, mayonnaise and honey. Spread the sauerkraut on the bread, place the sausage on top, add the mustard mayonnaise and fried onions.