1 Jar of Dona Maria Mole - help!

So I've never cooked Mole before but have this jar of Dona Maria. I've read some other posts about using it, and look forward to it. But, I'm more or less cooking for 2. I've got 2 little ones who seem to only want to eat chicken nuggets, pizza, and yogurt.

So I was looking at the Mole jar last night, and it looked like it was a lid that you didn't put back on after you opened it. How do you store it after you've opened it up? I don't expect to use the whole jar for the amount of Mole I would like to make, but then again, I've never done this before so I know squat!