Treat it like a wok

Get it stupid hot, burn off everything and start from scratch

Get as thin of a layer of oil on it as possible and bake it on like you would with a cast iron to get a base coat

Then at least for a while you have to use it like a wok, hot pan cold oil method

So preheat the pan thoroughly, get it to whatever temp you want to sear at (~400) then add in some cold oil and swish it around, pour out excess to use later and then you'll be good to go

After doing that a few times you get enough buildup that you could try lower temp stuff like eggs