I heat a skillet and lay them in it until they are browned on one side, then flip them over and cook until done. The preheated skillet makes them seared on the outside like you'd get with a grill, only no grill marks, of course.
Are you serious? lol.
Most people get a pan and cook them on the stove.
You make the patties, get a pan, place them in the pan, turn it on about 5-6 for heat, let them cook. Don't let them cook on higher, the outside will get done, but the middle won't.
Flip them until they look thoroughly cooked.