Can’t get that nice brown crust

Basically the title. The steaks were great but I didn’t manage to get that nice brown crust I see on many pictures. I did use a frying pan and butter, and yet…

What am I doing wrong?

Basically the title. The steaks were great but I didn’t manage to get that nice brown crust I see on many pictures. I did use a frying pan and butter, and yet…

What am I doing wrong?