I'm using a charcoal fired grill, so the first step is to fire it up as it can take up to an hour to make it nice and hot.
Remove any silver skin from the pork tenderloins, we don't want this in our steaks. Cut each tenderloin into 3 pieces.
Make the marinade by simply mixing all the ingredients listed. I recommend to give the marinade a taste to make sure it's salty enough. Our pork tenderloin steaks are rather large, so the marinade needs to be a bit over-salted.
Place the tenderloin steaks into a bowl with the marinade and use your hands to cover each piece properly.
I start by grilling the potatoes first. When using small ones, there is no need to pre-cook them. But to save time, I did that.
Once potatoes look good, move them away from direct heat and start grilling the pork tenderloin steaks.
Grill from all sides, including the ends/tips. 3-4 minutes per side for medium, more if you want them well done.
Place the finished tenderloin steaks into a small pot, add some butter and let it melt. Toss the pot, cover with a lid and let rest for a few minutes.
Now the potatoes. Add them to a bowl, put some butter, thyme and rosemary in and mix carefully. We want the butter to melt and coat the potatoes without breaking them.
Slive the steaks before serving, then pour the mushroom sauce all over it. Serve with the potatoes, about 4-5 pieces per serving. Recipe for the mushroom sauce is here: https://cookwewill.com/creamy-mushroom-sauce/