I love the store-bought sardines packed in mustard and tomato sauce. Last year I bottled some. The tomato/Tabasco ones turned out tasty and I was happy with them. But the mustard herring were not so good. They tasted good as bottled herring goes but they weren't like the kind in the store. I tried just squirting a blob of prepared mustard inside and it just turned out to be a brown, tasteless blob on top of my herring. I tried ground mustard just because that's all I had. We have a jillion small herring in our bay right now. I have perused the internet trying to find a good bottling recipe for sardines/herring in mustard sauce but I can't find anything. Does anyone have any recipes for this or suggested ingredient I could try?