It's tricky to translate foods/ingredients, but if you can look up the scientific botanical name using the Italian Google and then search for that name in the English Google, you'll potentially get a better translation.  I think it's just mint that you used.  Catmint is in the mint family, but it's a particular kind of mint that you buy in pet stores generally.

Parma ham, like speck, is another one that Americans won't necessarily be able to find in the typical grocery store.  American bacon is different than what you can find in Europe generally, and American ham... well, you would probably prefer American bacon in this recipe over the American ham.

I can find Parma ham, speck, etc., but I have to go to one of the fancier grocery stores and remember which one has what.  It's not in the typical grocery stores, and I also live in a city that has fancier grocery stores in addition to Indian, Mexican, Chinese, etc. specific stores.  If I lived 30 miles away, I wouldn't have access to all that or would have to drive 30 miles.

My husband and I have also encountered recipes with hard-to-find ingredients, especially some of the Indian ones, so we have to look up what the ingredient actually is, how it tastes/feels, and substitute the best we can.  I can't imagine doing that with certain American recipes because there isn't a good substitute for things like Oreos, Cream of Mushroom soup, Velveeta, etc.  They're all commercial products that are easy for Americans to purchase, and it would be a lot of extra work if you had to make the Oreos or the Cream of Mushroom soup from scratch.  I have no idea how to best substitute Velveeta (you know, fake cheese) except to use a cheese that melts easily without becoming stringy and doesn't have a particularly strong flavor.

Looking up lesser calamint, does the herb you use smell like oregano and mint if they were combined?