Cooking over an open flame at home
It is similar to cooking over a propane grill. Gas grills often have stone or ceramic bricks in them to help retain heat, but it is the burning gas that provides it.  Cooking over a gas stove should be similar.

That said, I wouldn't grill meat or fish directly over the flame; it may work, but the cleanup may not be worth it.  If you want to char a pepper or some bread and get the 'grill' feel, that should work fine.  I see chefs do it all the time on TV, and it looks easy enough and doesn't make a mess.