Good thread for tying meat I want to prepare kotlet de volaille. It'a a bit like Cordon Bleu, but using the natural pocket in chicken breast, and inside is just butter and fresh herbs.

I thought about tying the meat with a thread, like a roulade, but I've never done this before, so I don't know what kind of thread to use. Is there a special kind of thread of will my polyester sewing thread be enough?

It took me some time, but I found the name of the dish in English - Chicken Kiev.
For something more delicate than kitchen twine, any thread from a 100% natural fibre (cotton, hemp) should work.  Synthetics (polyester, rayon, nylon) could melt or offgas into your food when subject to high temperature.