For us, the market is also about the people. You have nice exchanges. (Some not so nice, too.) And, you learn a lot.
There were two varieties of cilantro on the seller's table. There was the kind most people recognize, sold with the roots intact. Use the roots! The other type was very tall stemmed with wispy leaves; what gardeners call overgrown plants going on to form seeds, "bolted".
Jacinta recommended the overgrown type. Of course, the next thing that came up was what to do with it?
Sofrito in any Spanish related cuisine is a flavor base made with a mixture of aromatic vegetables. It adds depth and complexity to soups, stews, braises, rice, beans. It is common practice to make a big batch and freeze portions for use later on. Sofrito may be Latin in it origins, but it is quite versatile for a lot of dishes; in a sauce with pasta, for example.
Jacinta spoke of a mixture of pureed onions, garlic, and cilantro. Culantro? Yes, of course. She was impressed that us Gringos even knew about culantro. If you don't know from culantro, then here's a hint: Shado Beni. (Cooky Cat is not going to exhaust himself with lengthy lessons on what's what. Search it, silly.)
Mostly, a big issue for Jacinta was about not using things that add a lot of moisture; for example, green and red peppers and tomatoes. She was of Pueto Rican descent and evidently tomatoes don't go into sofritos on that island. She didn't like the green bells either, so maybe a little red pepper. But, searching around you will see the addition of green and red peppers, sweet cubanelle peppers, and aji dulce peppers by some cooks. There are probably as many variations for sofrito as there are cooks. So, suit yourself.