Have two skillets ready and a firm metal spatula.
Pre-heat one pan over a medium to medium-high heat.
To test if it is hot enough, drip a drop or two of water in it – it should sizzle.
I use a very thin spray of avocado oil. However, this can be done with no oil, but I recommend beginning at a slightly lower heat – medium to medium low.
Sprinkle your seasonings over one side of the mushroom and put the seasoned side down in the hot pan. Take your other pan and press it on top. Hold it there with pressure for 30 seconds or so, then leave it to cook (with a weight on the pan if not using cast iron – like a large can of tomatoes) for about 5 minutes or until a fair amount of liquid has released from the mushroom.
With your spatula carefully flip it and season the up side, put the pan on and press again and cook for another 5 or more minutes. Season and flip one to two more times or until both sides have a nice golden color and most of (or all) the liquid has been absorbed. You are aiming for golden brown.
Heat a grill (or grill pan if cooking in the kitchen) and baste the mushroom with your favorite barbecue sauce and place the basted side on the grill and cook several minutes, baste the top and flip and cook until both sides have char marks and the some of the ends are blackened (kind of like a steak).
Remove from the heat onto a cutting board and slice diagonally into strips to serve, with some more sauce on the side. This is great on a sandwich, taco or in a burrito.