A few years ago, my husband and I discovered a bizarre phenomenon. After a few days of everything he ate tasting bitter, my husband decided to Google this weird sensation in his mouth. What he found was a bunch of articles and hundreds of comments about the connection between pine nuts from China and the bitter taste. Apparently he was not the only one. The sensation started a day or two after he had pasta with pesto sauce in a good Italian restaurant in New York. A year later, the same thing happened to my sister and I after we had a salad with pine nuts. After we finished the salad, I joked and said to my sister, “I hope the pine nut are not from China.” She was skeptical, but two days later we both had this awful bitterness in our mouth. Since then – and since Spanish pine nuts are expensive ($28 per lbs. at Whole Foods!) – I now use pumpkin seeds, slightly roasted, in place of pine nuts. The taste is slightly different, but just as excellent as traditional pesto.