Crock Pot Wednesday: Vegetable Stock

I seem to have a lot of extra carrots, celery, and onions in my kitchen recently. I decided to try a vegetable stock.  I looked at a bunch of different methods and recipes and this is what worked for me in my kitchen.
Combine:
4 cups of water
carrots
onions
celery
1 tbsp olive oil
garlic  ( cooked the garlic and some of the onion in the oil before adding it to the pot for flavor enhancement. )

From what I read these are the KEY ingredients.  Just add what you have or what sounds good to you.  (I also had some squash and mushrooms that I added.)

Cook on low for 8-10 hours.  Strain vegetables through a cheese cloth or very fine strainer for best results.

I was able to get 6 cups of broth in my batch.  I portioned it and put it in the freezer.  I am looking forward to using it in soups and stews later this winter.