Start by taking the steaks out and letting them sit at room temperature. You really want them to sit at least a half hour before you put them on a hot grill. I used bone-in sirloin strips this time, but any steak you like works with this.
While that comes to room temperature, start with the onions. Red onion is my go-to, but white or a few yellow are also tasty. Slice and saute in a mixture of olive oil and a few tablespoons of butter, seasoned with salt and pepper.
It takes at least a half hour to get onions properly caramelized. You want them to be very soft and browned, but not blackened. They become very sweet when cooked way down this way.
While these are working, prepare your mushrooms. You can use any you like, though I find that regular button mushrooms really don't have much flavor. I really love criminis, which are baby portabellas. When I can find it, I get the mix packs. For this I used criminis, oysters and shitakes.
Mushrooms usually need a quick cleaning, but can get too waterlogged and rubbery if you run them under water. A wet paper towel and a quick brush off of any visible dirt is all you need. I like to cut them into large chunks.
Once the onions are caramelized, add these right in.
Cook them for about 10 minutes, until they brown up and wilt a bit, then add in the thyme. I like to strip a few stems and mix in the leaves, and also to throw a few stems in whole and then pull them out after.
Mix that up and let it cook on low while you prepare your steak. Then, when the steak is resting after cooking, come back and finish it off.
I cooked this steak on the charcoal grill. I alternate between that and the gas, though I've been on a gas kick lately, and I think steak tastes best when cooked over charcoal. Get the grill roaring hot, and then to about medium high (our grill has a grate where the coals can be raised or lowered with a crank, so I lower it a few inches). Season the steak with salt and pepper and drizzle a little olive oil, then on she goes.
For a steak of this thickness (1-1 1/2 inches) to be medium/medium rare, I cook for about 6 minutes on the first side and 3-4 on the second. It takes some practice, but eventually it's something that can be determined by touch. The steak will be a bit soft and bounce back in the middle at that doneness when you press on it.
While the first side cooks, I test the wine I'll be using in the sauce. Grilled asparagus will be our side this evening.
When the 6 minutes are up, flip and cook the second. How long it takes will depend on how hot the grill is and how well you want it cooked, so give it a poke after two minutes or so and keep testing. When it's done, pull off and let rest for at LEAST 10 minutes. Cutting the steak too early will make all the juices run out and the steak will be dry.
We usually tend to do one steak/two people around here, and load up on the veggies, so this steak is for Johnny and me (and whatever Declan can steal once he's full of vegetables himself. Kieran, of course, will have peanut butter and jelly).
While the steak rests, it's time to finish the sauce. Turn the heat back up and add in the red wine. It will boil up a bit, and this is when you scrape the pan to deglaze. Then, while it simmers, add in another pat of butter to finish off the sauce.
Once the wine has reduced down and the sauce is a smooth, silky consistency, pull out the thyme stems. Spoon over the steaks and serve. Try to resist coming back to the pan and eating the rest straight out with a spoon. Though it you do have leftovers, they are delicious over a piece of charred crusty bread.
Grilled Steak with Thyme Red Wine Caramelized Onion and Mushroom Sauce
Steak of your choice
1 large red onion, sliced
1 pint of mushrooms (crimini, oyster and shitake used here), roughly chopped
5 sprigs of thyme, 2 with leaves stripped, 3 whole
3 TB butter, divided
3 TB extra virgin olive oil, plus more for drizzling on steak
1 cup of good red wine
Preparation
Pull the steak from the fridge, remove wrapper, and let sit until it comes to room temperature, about a half hour.
While the steak us resting, prepare the sauce. In a large, heavy bottom skillet (I prefer cast iron, but stainless steel is great too), heat 2 TB butter and 3 TB olive oil over medium-high heat. Slice the onion and add to the skillet. Cook them until they start to brown and give off their juices, stirring often. Turn the heat down to medium/medium low and cook until onions are caramelized, about 30 minutes. While onions are cooking, wash the mushrooms by brushing them with a wet paper towel. Roughly chop and add to the caramelized onions. Cook until they are wilted and browned, about 10 minutes. Add in the thyme leaves and sprigs and stir to combine. Turn the mixture low while you prepare the steaks.
Heat your grill to medium-high (if you are using a charcoal grill, start the coals around when you put on the onions.) For medium/medium-rare steak, cook for 6 minutes on the first side and about 3-4 on the second for a steak 1-1 1/2 inch thick. When the second side is cooking, press your finger in the middle of the steak. If it springs back after 2-3 minutes, it's done. If you like it more well, wait until it's got less give when you do a finger press. (*Note: if it's not grilling weather, this same principle applies to indoor cooking. A cast iron skillet is my favorite indoor steak cooking vehicle.)
Let the steak rest for at least 10 minutes once it's done. Meanwhile, turn the heat back up on your sauce. Once it starts to sizzle, add the red wine. Scrape the pan to get the cooked on bits up and stir to boil. Reduce to a simmer and add the last TB of butter. Cook until the sauce reduces, thickens, and becomes silky, 2 minutes or so. Pull the sprigs of thyme and serve over your steak. (Also great on crostinis).
