Because we're eating gluten-free, I changed a few ingredients but I'll give the original and add the changes in parenthesis.
Saute a bit:
5 T. finely chopped onions
10 T. butter (or coconut oil)
Stir in and heat till smooth:
3/4 c. flour (or tapioca starch)
1/2 c. sugar (or rice syrup)
5 tsp. sea salt
1 1/2 tsp. pepper
10 c. tomato juice
(I added a cup at a time to avoid lumps several times)
Fill jars to within 1/2 inch and water bathe 1&1/2 hours.
If filled too much, it will cook over and run out of the jars.
Follow the usual rules of canning!
When I serve it, I dilute it with water but milk can be used - either way it's good!