Sunflower seeds come from the large flower that follows the sun, which reached Europe from the Americas. They are small, inexpensive and very versatile.
Dry-toasted for a few minutes they become crunchy and fragrant, and flavour salads, sauces and crostini. Blended with raw vegetables and a little oil they give body to pestos and sauces, like my rocket sauce; in a celery leaf pesto they replace the more expensive pine nuts. I also use them in plant-based cheeses, with cashews and almonds.
Buy them shelled and plain, not salted, and keep them in a closed jar: being rich in fat, they can turn rancid in the heat.