Why are oils commonly used? Oils are commonly used in pan frying to avoid sticking, to use high heats to cook faster, and to carry flavors. Each of these is just a convenient technique for a cooking problem and result, but none of these is the only way to get the desired result. Historically oils would have been both expensive and prone to spoilage. Preference is matter of choice, and while one choice is convenience, another choice is quality and simplicity. My preferred technique uses the flavors and tastes from ingredients in their fresh and whole natural packages, going a bit slower, and emphasizing quality. Let's look at each problem and how to get the desired results.
- Avoid Sticking: To avoid sticking, use a non stick pan, lower the heat, and deglaze with a splash of water. All three of these avoid the burning and sticking that using oil also prevents. Which gets used depends on circumstances. Often I use regular saucepans to brown onions, or mix flavor bases, stocks and gravies.
- High Heat (Browning): To brown vegetables, especially onions, just go low and slow. Browning takes heat, dryness and alkalinity, but not necessarily high heat. You get dryness when the surface moisture of your vegetable is vaporized. Then the outside starts to brown. Cutting smaller and thinner helps evenly dry and then brown your vegetables. If you must go hot and fast, use a non stick pan. Alkalinity is usually fixed by your vegetable ingredients, but you can, for example, add baking soda to onions to increase alkalinity and brown onions faster. Don't bother, it adds nothing to flavor.
- Carry Flavor: To carry flavor just use water or vegetable purees. All whole plants also contain some oils that are released into sauces. Add ingredients like spices early to the base to allow flavors to absorb and mix. Moisture carries flavor better into dry ingredients like grains and pulses.
To summarize the methods to cook without oil:
- Use non stick saucepans particularly for higher heats.
- Lower heat and go slow to brown.
- Use vegetable bases and water to carry flavor.
Spices: Use medium-high heat, with non stick pan. Toast the spices in the non stock pan, then set aside to cool and grind. Then mix the ground spices into stock, soup or gravy, where water and moisture, not oil, infuses and spreads the flavor. Recipes commonly fry spices and herbs using oil. Note you can not grind oily spices. So this usually means keeping duplicate powdered spices in the pantry. I prefer to toast whole spices first, to dry and enhance flavor, then grind whole spices into mix or powder. When discussing spices, I mean the whole dry spices that store well, not fresh herbs. Most herbs are more delicate and should be simmered at lower heats. For example, garlic can easily burn and become bitter. Herbs don't get toasted and instead are add to the moist flavor base.
Onions: Use low heat and go slow. Recipes commonly fry onions at high heats to brown them faster. If you're not working as short order cook, brown your onions low and slow. They don't burn as easily. You can also brown a couple of onions in batches that keep refrigerated for up to 3 days, which really cuts cooking times.
Vegetables: Use medium heat and non stick pan to roast and brown the outside of vegetables, like potatoes and sweet peppers. Use a tight fitting clear lid for keeping steam and keeping an eye on the vegetables, sometimes adding a spash of water. Lightly brown the outside of vegetables before adding to dishes like curries.
Stocks and Soups: Use liquids to carry the flavors. Add whole or ground spices, brown onions and roasted vegetables directly to water in cooking stocks and soups. Stocks and soups are are easy to cook without oil. Stocks and soups often cook dried ingredients, like rice and pulses. Water moisture makes this possible, not oil. When the dried ingredients absorb water, they both absorb the flavor and give back to the flavor of the stock and soup.
For more details, see my recipe tips for Toasting Cumin and Browning Onions.