all I do is open a bag of Trader Joe’s frozen french cut green beans (i think french cut are the best kind) and dump them onto a giant sheet pan. take off any large ice chunks you see but don’t sweat it if there’s still some frostbite. it’ll sizzle off in the oven
I pop them in a 400° oven for about five minutes to defrost. I then pulled them out and toss them in EVOO. Put them back in the oven and roast for 15 minutes. Pull them out, shake them around, and put them in for an additional 10 minutes. This gives you a very wonderfully crispy green bean. Decrease the roasting time if you don’t want them quite so crispy. Top at the end with fresh ground sea salt and you have the most delicious side to any meal! i always, always have at least one bag in my freezer.
ps—they reheat in the oven (or even in the microwave!) like a dream