I agree that the sauce was too thin, but we all liked it anyway. I did not add the mustard, but instead used 1/2 Tbsp Worcestershire Sauce. Adding a few uncooked egg noodles (maybe 2-3 oz) and cooking for about 1 hour at the end worked wonders to thicken it, as they absorb liquid and fall apart. You could serve with some extra noodles to your liking. It didn't make sense to me to add the flour so close to the end. I added it at the beginning, stirring it into some of the water and then dumping that into the pot.