Rachel Roddy’s recipe for spaghetti with prawns, courgettes and gremolata | A kitchen in Rome

Memories of an old teacher and friend inspire a plate of pasta that’s just in time to welcome the new season’s courgettes

While tidying the freezer the other week, I found yet another reminder of my (late) friend and teacher Carla Tomasi in the form of a Tupperware box a bit larger than a matchbox. Unlike the rest of the unmarked boxes with identical sky-blue lids and opaque sides, I knew exactly what this was: a mix of parsley, garlic and lemon zest (otherwise known as gremolata or gremolada) made last June to go with braised chicken, but not finished, so the leftovers were put in the freezer. I exchanged messages with Carla all the time and, knowing how much she loved freezer-talk, I consulted her as to how long she thought the mix would keep in there. She gave two replies: an official one of three to six months, and an unofficial one of a year, which must have sunk into my unconscious like a preset alarm because, almost a year later (and 10 months since she passed away), I find myself in front of my chaotic freezer, holding a tub of finely minced things and thinking, “There you are!” and, “Thanks, Carla!”

Gremolata is a typically Milanese mix, and the name means to reduce into grains. And that is precisely what you do to a clove of garlic, a handful of parsley and the zest of a large unwaxed lemon in order to make a fine and fragrant rubble, which can be made by hand or in a food processor. While gremolata is closely associated and served with braised osso buco and risotto alla Milanese, it is a fantastically versatile addition to all kinds of other dishes. Even though it can be used raw, the best of gremolata is brought out by heat, which wakes up the garlic (and softens its pungency, too) and the natural oils in the lemon zest. Also in my freezer were some peeled prawns; not a year old, but nearing freezer burn.