In a large saucepan over medium heat, mix together the chili sauce through to the cinnamon. Bring to a boil then reduce heat slightly and simmer for 5 minutes. Let cool. Stir in 3/4 cup water.
Put roast in the slow cooker. Pour the sauce over the roast in the slow cooker.
Cover with the lid and cook on Low for 8-10 hours or on High for 4-6 hours (mine took 4), until meat is tender.
Remove meat from sauce and let stand for about 10-15 minutes. Then shred using a fork or carve into slices. Put meat on one half of the bun and top with the sauce and the other half of the bun.
Recipe by Just a Smidgen at https://justasmidgen.com/2012/11/03/my-new-buyphone-5-and-macbook-pro-se/