Roux in a jar for turkey gumbo question

When using jar roux, I whisk it into hot stock. I also cook my trinity in the rendered fat from the sausage I cook in a separate sauté pan then add that to my stock/roux

I sauté the vegetables and then add roux and a little stock/water. Blend well. Then add a little more liquid, blend, then repeat.

When I use jar roux, I melt it down and add a little grape seed oil to get it thin enough to sauté my trinity. Onions go in first to sweeten, then the other two. John Besh agrees on the onions thing.

I’ve done reverse, like Paul Prudhomme, and added roux to hot stock. It all ends up good, but I like the smell of the onions in the roux.

I pour out the oil, then use bacon fat to heat up the roux.