Preserving sweet onions

Okay, first, yes I know I've been distracted to other things lately. I'll try to get you caught up on the past six weeks gradually. But what is on my mind right now is sweet onions. I adore them, but storage is always a challenge. We got a bag at Costco a couple of weeks ago, and today it was "use 'em or lose 'em." So I cut a few of them Lyonnaise style (top to bottom. for crescents) and am cooking them very slowly to get a batch of caramelized onions, which I will freeze and pull out for burgers etc. The rest of them are diced and bagged for the freezer. They'll keep just fine for a while, and though I won't use them fresh they will be great when I want a sweeter mirepoix or am making Indian food. The last bit of them I am using in a casserole today using my homemade chorizo (Oh, yeah, I didn't tell you that I made chorizo for Cinco de Mayo, and also ginger/sage breakfast sausage, because I got pork shoulder for 88 cents a pound!) and some Mexican rice with zucchini and lots of chopped sweet onion. I might even mince up a fresh jalapeno, a couple are ripe in my Aerogarden.