Thai lava chili: how could I reproduce this?
I generally associate the phrase "chili jam" (also known as chili paste) with store-bought sauces, like this one.

It wouldn't surprise me if they were using a very similar ready-made sauce - perhaps they get it from a distributor or perhaps they even make it themselves in large quantities and store it, but I doubt that they make it from scratch for every meal - few Asian restaurants do.

If the dish you were served doesn't contain ground beef or any of the things you'd traditionally associate with American chili (other than the thick consistency) then this might be as simple as whipping up a stir-fry using a store-bought chili paste.  If it's too thick, add a little soy sauce.  If you want more tanginess, add some lime juice.  If you want more sweetness, add brown sugar.  And if it still seems to be missing that certain je ne sais quoi, you might need Thai fish sauce, which you find in almost every Thai dish.

I hope that helps.  If it doesn't get you where you want then feel free to report back and explain how it turned out differently from what you expected - one of us can surely take it from there.