Turn a cheap oven into a gourmet oven with an oven thermometer. You can pick this baby up at amazon.com for about $5.
I have a crap oven in our condo. I made some terrible meals before I found out that it was NOT THE CHEF!
I set “BAKE” to 300F, and she is set herself -275 degrees Kelvin.
Fabulous. It will take 3 years to cook chicken.
As a scientist and homemaker, I figured she needed calibration. So, I bought an oven thermometer and sure enough.
On the low end, she is off 25F. At 400F, things even out.
Give it a try.
You have probably been a gourmet chef all this time.