I trust your using a cast iron skillet for this masterpiece? Should be able to hold the heat needed to form the crust your looking for and eliminate the need to rotate the patty.
I am. Normally, I get even heating, but normally I'm not cooking on such high heat. Of course, I'm probably not waiting long enough for my skillet to heat up.
Might try using a cheese grater for the minced onions....that's what I use.
I use a mandolin slicer that has a very fine julienne attachment. When done with an onion, since it's layered, they come out in little rice size pieces. Perfect for the paste I'm making.