To prepare squash blossoms, gently reach into the center of each, pinch out the stamens or pistil, and discard. Rinse the flowers carefully and invert to drain. You can cook all blossoms with the stems, but some cooks don't like the texture of the straight stems (on the male flowers) and break them off first.
The easiest stuffing is cheese. Choose one that melts or gets creamy: a tangy chèvre (goat) or blue, a velvety fontina or cheddar, or cream cheese with a dab of grated parmesan. Fill blossoms sparingly (1 to 2 teaspoons each), then loosely twist tips closed. Cook stuffed flowers in melted butter in a frying pan over medium heat until wilted and tinged with brown, 1 1/2 to 2 minutes.
For a variation, you can dip the squash blossoms in all-purpose flour, then in beaten egg (fritto misto-style), and brown them in olive oil with a few cloves of unpeeled garlic.
Nutritional analysis per 2 stuffed blossoms (cooked in 1 teaspoon butter).