Of all the Thai home cooks I know, the most creative ones are the Thai students living in university dorms in the United States. I mean it. The levels of competence, of course, vary among them. But the creativity that goes into churning out the best and most affordable home-style Thai dishes that deliver much more than they require is astounding across the board.
Look at this simple thing that asks for only six ingredients—seven, if you want to add extra umami to it by way of oyster sauce. This is very practical for those living overseas in a small space with an electric frying pan, a microwave, and a refrigerator the size of a shoe box. But the result feels like a hug from home. The people I know have made one version or another of this on a regular basis.
It's very versatile as well.
Don't like green beans? Use canned bamboo shoots. Don't like chicken? Use quick-cooking cuts of beef or pork. Like seafood? Use shrimp or squid. If you can find fresh Thai basil, add a handful towards the end. If you can find fresh kaffir lime leaves, slice a couple of them up very finely and throw that in too. Don't have either of those? Forget them. I wouldn't allow my inner happiness to be regulated by the scarcity or abundance of some herbs.
Have some stir-fry left over that's barely enough to feed one when you need to feed two? Throw that into a frying pan along with some cold rice and make a fried rice out of it.