Just Three (Leftovers): Rib Eye, Mac-n-Cheese, Onion Marmalade

Stove-top Rib Eye, basted in Butter and Fresh Herbs

A clear violation of my self-imposed rules of "Just Three", using leftover like this, but the principal advantage of blogging, and self-imposed rules generally, lies rooted in the simple fact that one may ultimately do whatever one wishes. Of course, your readers may kvetch, but that's part of the game.

I could drape my transgression with pearls of wisdom and wit, or I could lean on my earlier arguments (e.g., here, and here) that leftovers play a fundamental role in the kitchen - the avoidance of waste, the efficiency of leveraging time already invested, and, above all, the enforced discipline of making something new out of something old - but the simple truth is that I cooked for company last Saturday night and one of the invited couples was a late-day no-show. Ergo, come Sunday, I had a spare steak (a rib eye from Painted Hills, who really do things right, by the way) and several cubic meters of seriously high-density Mac-n-Cheese (recipe forthcoming from the thread started here). I was also pretty sure I had some more of my spiced onion marmalade somewhere on an upper deck, and a plan came together, a plan with the elusive trifecta of zero prep, zero shopping, and a single pan.

Stove-top Rib Eye with Spiced Onions and Mac-n-Cheese

1. Get a good rib eye. Make sure it's thick - less than an inch and you'll struggle to get a crust on the outside and keep it rare and juicy on the inside. Try to get one that was grass fed, humanely raised, nicely marbled. Or buy whatever you want, I'm not a zealot about it, but it will taste better, be better for you, and let you sleep easier knowing your cow had a nice life before being brutally slaughtered for your dinner.
2. Take the mac-n-cheese out of the fridge cold, and cut it into cylinders using a biscuit cutter. Warm them - SLOWLY, or the cheese sauce will break - in the oven. Maybe 250? Or, horror of horros, nuke 'em on low power. Warm the onions (and yes, a microwave is perfectly acceptable for this task, just be sure to stir them afterward).
3. While the pasta is warming, get a cast iron pan good and hot (the rarer you like your meat, the hotter), and season both sides of the steak liberally with kosher salt and pepper. Put a knob of butter in the pan and add the stead as soon as the butter foams. Toss a few sprigs of rosemary and thyme and a couple cloves of whole, peeled cloves of garlic in the pan while the steak is cooking - this will smell incredibly good, and adds a subtle but impossibly good aroma and background flavor to the meat. Once you turn the steak, baste it repeatedly with the herb-infused butter and fat in the pan. 
4. Do not, not, NOT overcook the steak - it will taste crap, and it's an insult to the animal that died for your pleasure. Also, remember that it will continue to cook as it rests (and it must rest - good discussion here). Please try to avoid the temptation to cut the damn thing to see what it looks like; use a probe if you must but, if you're going to cook steaks, you need to get over the temperature thing and just go by the feel of it when you press down gently (you can gauge the done-ness of most proteins by comparing how it responds to pressure to the flesh of your thumb muscle, or whatever that muscle is called, as shown here, although you'll have to tweak those guidelines to your own hand and musculature).
5. After the steak has rested, slice thinly and layer on the plate, alongside a mac-n-cheese cylinder and a quenelle of the warmed onion marmalade.