The last time I tried to tackle squash flowers, when I took them from the fridge a couple of days after buying them they had already turned to mush. So be warned, work quickly. They are best used the day of purchase.
The squash flowers here are not actually the same as the flower you see attached to baby courgettes, the squash flowers here are the flowers of a larger tougher vegetable.
There are a couple of recipes using the flowers in soups. The recipe I tried is pretty much directly from Rick Bayless with little modification. It is Flores de Calabaza Guisadas or Stewed Squash Blossoms. The flowers are lightly stewed in tomato with a saute of onion and chile. This is used as the filling for a quesadilla.
Cleaning the flowers is easy, though they are delicate, and personally I find the hairs on the stem and leaves unpleasant to handle. The stamen needs to be pulled out of the inside of the flower and the sepals pulled from the outside. The flowers are then carefully rinsed and cut crosswise into 1/2" pieces.
Flores de Calabaza Guisadas
I sautéed a half of a medium onion, diced, in lard with chile. I used two finely diced serranos, but it's a matter of taste. When the onion had softened I added the flesh of a roma tomato which I had boiled, skinned, cored and puréed in a little water and about 20 chopped squash flowers.
I seasoned this and let the whole lot heat gently for another few minutes and finally added some small cubes of queso panela and a small amout of corriander and let the mixture cool on a plate before using in the quesadilla.
Rather than making a proper empanada style quesadilla of masa, stuffing and deep frying it, I took the quicker option of heating some corn tortillas and placing the filling inside a doubled over tortilla and heating this on a dry comal. This shortcut is regarded rather sniffily by Diana Kennedy, however it's also how I see the guys where I work prepare their lunches every day, so good or bad it seems to be a common approach, and the idea of deep frying a Saturday lunch was not an appealing one.
The blossoms made a pleasant lunch, but I think I'd like to try the couple of soup recipes before deciding on whether squash blossoms are an unusual novelty or something I'd buy regularly. Perhaps they were a little drowned out by the onion and chile, but to my palate - dulled by cigarettes and whiskey :-( - there wasn't anything very distinctive about them.