Can your knife easily slice through a tomato skin? If not, it’s time to sharpen it. (Photo: Getty) By Haley Scarpino I started moderating chef Julia Turshen’s online cooking classes in January 2022. Since then, we’ve been meeting a few Sundays every month and have racked up more than 130 class es, a number that surprised me when I actually tallied it up. There are so many reasons I love working for Julia, but the most important is that she’s really kind, and I love her practical approach to cooking. (Pictured: Julia, left, and Haley.) During the classes, which she leads from her home in upstate New York, it’s my job to answer questions and make the participants feel comfortable and cared for, which I enjoy. I keep a close eye on the Zoom chat and get Julia’s attention whenever there’s a question I can’t answer myself or something that would benefit the whole class. So over the last four years, I’ve answered many (many!) questions. Here are three of the most common. “How often should I sharpen my knife?” The answer is both simple and annoying: You should sharpen your knife as soon as you notice it’s dull. It’s truly that simple. The time it takes for your knife to go from sharp to dull depends on how much you use it and how well you take care of it. A sharp knife should easily slice through a tomato skin. If yours doesn’t, it needs sharpening. I recommend using a good-quality electric sharpener or taking your knives to a professional for sharpening. My favorites are Kitchen Collage in the East Village or Edgetech Sharpening in Valley Junction. Between sharpening, I recommend honing, which is not the same thing. Honing realigns a blade’s microscopic edge, which bends and rolls during regular cutting, and prolongs the interval between sharpenings. Always wash and dry your knives by hand and return them to storage. That helps keep your knives sharp and in good condition. “Can I substitute x for y?” When deciding whether and how to make a substitution, consider the ingredient’s role in the recipe. Does it add a salty, crunchy or fresh element? Is it a leavening agent? Does it hold things together? Flaxseed, for example, makes a great substitute for eggs as a binding agent in baked goods. Once you determine each ingredient’s purpose, you can substitute something else that does the same thing. One thing to keep in mind: You may have to adjust cooking times for proteins. Fish and beef, for example, require less cooking time than chicken. And different parts of chicken require different times: chicken breasts should be cooked to 165 degrees while thighs, with more fat and connective tissue, should top out at 185 or 195 degrees. It’s smart to have a good instant-read thermometer. My simplest advice for substitutions is to use an ingredient you love. If you don’t like tarragon and a recipe calls for it, use a different fresh herb you do like, such as parsley. That said, it’s a good idea to try new ingredients regularly. Just taste them before you toss them into the dish. “Can I use a different-sized cake pan?”  The answer is always “yes.” You just have to adjust the cooking time. Julia has some of my favorite baked good recipes. Her first cookbook, “Small Victories,” features the best chocolate cake, called “Happy Wife, Happy Life.” Her most recent book, “What Goes With What,” offers her Morning Glory Muffins and Easiest Almost Cake, which lives up to its name. She makes a lot of baked goods in class, too, and they’re usually made in one bowl and can be baked in any size pan. Remember, the thinner the cake is, the faster it will bake. A loaf pan makes the thickest cakes, so those bake the longest. Muffins are usually small, so those bake relatively quickly. There are also many good online resources to help you decide how long to bake something in the size of the pan you’re using. I usually point people to this chart from The Spruce Eats. It’s always wise to plan for a little less time, keep an eye (and nose) on your baked goods, and test them with a toothpick or skewer. Once your kitchen starts to smell delicious, it’s usually an indicator that whatever you are baking is done. Julia teaches a few Sundays a month, and the menus change weekly. This Sunday, she’ll explain how to make “A Beautiful Inexpensive Vegetarian Meal,” including Llubav’s green spaghetti; warm white beans with parsley and garlic; an orange, olive, and onion salad; and polenta cookies. In addition to her classes and cookbooks, Julia hosts a podcast and recently wrote a queer romance novel, “Down to Earth,” that will be released in June. Haley Scarpino is a chef, home cook, recipe tester, food editor and graduate of the Iowa Culinary Institute. She lives in Beaverdale. ...read more read less