Zucchini with pine nuts are cooked to the texture of butter, tart with lemon and perfumed with fresh herbs. (Robert Lachman / LAT)

The next night at dinner at Delfina in San Francisco, there they were on the menu again, this time cooked longer in a chunky tomato sauce. Not wishing to buck a trend -- certainly not one as delicious as this -- the next night when I cooked dinner for some friends, I braised the beans with chunks of browned pancetta, finishing with chopped cherry tomatoes and basil.

As Romanos cook, their texture changes. At first, they are like fatter, denser green beans; a little longer and they turn rich and meaty. Braise them until the pods start to separate and fall apart, though, and they turn positively silky.

Brighten with mint

YOU can braise zucchini that way too; the texture becomes downright buttery. Brighten the rich, sweet flavor with mint and lemon and add some toasted pine nuts for crunch and contrast.

You can even braise bell peppers. I found this recipe in my friend Faith Heller Willinger's new book "Adventures of an Italian Food Lover" -- she got it from her friend Carla Galli, a maker of artisanal aceto balsamico (this is the profound, aged, syrupy balsamic vinegar, not the thin sweet/sour industrial kind).

Befitting its majestic stature (and price), the aceto should be drizzled very sparingly as a condiment just before serving and after the peppers have cooled to avoid damaging the vinegar's flavor. Using only a teaspoon will turn the dish from something delicious into something grand.

And if you can't find a great aceto, this will still be very good if made with a top-quality Sherry vinegar or red wine vinegar.

You've probably noticed by now that some sort of acid -- vinegar or lemon juice -- is a prominent component of each of these dishes. That's because without it, those luxurious textures and rich flavors can seem unctuous.

The acidity gives the dish the backbone it needs to avoid feeling flat and heavy.

Because the acidity is so important, be sure to taste and add more, if necessary, just before serving. Particularly in these dishes, acidity is every bit as important a seasoning as salt.

And because the vegetables are served at room temperature, they may require a little more seasoning than you might expect.

Remember that heat exaggerates flavor, whereas cold minimizes it. What might taste perfectly seasoned right out of the pan may need a little boost by the time it is ready to serve.

The good news, though, is that except for that bit of tweaking, these dishes can be made well in advance of dinner. Fix them in the morning, when the kitchen is cool (or even the night before). The flavors will improve as they stand.

Just be sure to bring them to room temperature before serving. When it comes to well-cooked vegetables, it's better to be cool than to be cold.