One of my first jobs in the food world was working for a French pastry chef. I was just the cashier for his bakery, but I hung out in the back a lot. The best lesson I learned from Marcel was not to waste. He would use his thumb to scrape the last drop of egg white out of the egg shell. (“That’s the profit,” he would tell me.) No wonder I never throw away chard stems or Parmigiano-Reggiano rinds. The cheese rinds add body and flavor to bean soup, and I’ve recently learned that they make amazing stock.