at the top of this page I had some steps to making mayo with some wasabi for mustard. I had no trouble keeping the stuff around for 2 weeks. On this one I made it into salad dressing by adding a load of blue cheese to it...

http://downhaul.com/lowcarb/keto141-168/

Let me know if you need step by step. You can do it without a stick blender, just a whisk, at least that's the way I do it.