These two dishes are on the same page because they’re cooked on the same clock. The potatoes need an hour in a hot oven; the chops need fifteen minutes over coals and ten minutes of rest. Get the potatoes in first, light the chimney about thirty minutes later, and everything lands on the table together. The method below is written as one timeline rather than two recipes.
When you toss the potatoes in the fat and they leave a thick starchy smear behind in the bowl — that isn’t a mess, that’s the crust forming. Parboiling brings starch to the surface, and roughing that surface up gives the fat something to catch on. Don’t toss gently and don’t rinse the bowl until after.
Marinade left sitting on the surface will steam instead of sear, and the garlic slices will scorch on the grate. Paper towels, both sides, right before seasoning. It feels wasteful and it isn’t — the flavor already went into the meat during the marinade.
Lamb loin chops are at their best at 130–135°F and lose their tenderness past medium. The covered rest on the cool side is where you dial it in, and a thermometer earns its keep here — on a cut this expensive, guessing is the expensive option.
Small jars, near the specialty meats, the charcuterie case, or sometimes shelved with the oils and vinegars. Butchers and specialty grocers reliably carry it. Once opened it keeps in the fridge for months, so one jar covers several dinners.