A couple notes: I did forget to mention that you should pour a layer of olive oil on the top to keep it fresh.
I tried it today spread thinly on a sandwich, and it was great. I also liked it on Sweet Onion potato chips. Don't judge me.
On Thursdays we have a potluck-style salad at work. I generally bring bread and greens and some other item. Tonight I peeled a sweet potato, diced it into about 1/2 inch pieces, and coated it in the same harissa/olive oil mixture as yesterday (2 Tbs of each). Then I roasted it in the oven for 40 minutes at 450 degrees.
I only sampled one piece to see if it was any good, and it was. I'll take it to my saladeers tomorrow and warn them that it's got just a touch of spice. [Added 4/28: They were good!]
I think the harissa sort of got a chance to rest and let the flavors marry overnight. I tasted the caraway more, which I was hoping for. In short: even better the second day. I think we're about halfway through the jar now, yikes!