In the last two months Flourish with Food focused on easy ways to address the challenge to consume enough health-promoting vegetables – an integral component of the Mediterranean way of eating (  This month, the focus is on healthy cooking methods to maximize their nutrition.

First to cook or not…raw versus cooked? The best answer is to always eat vegetables however they most appeal to you!  

Vegetables are nutritional powerhouses of fiber, antioxidants, phytochemicals, vitamins, and minerals that promote health and prevent chronic diseases (  How they are cooked makes a difference in best preserving nutrients and their availability in the body.

Eating only raw vegetables is not the answer. Heat breaks down the plant’s cell walls making them less rigid; thus, easier to chew and digest. Nutrients then become more available to the body. Examples of availability: cooking tomatoes makes the desirable phytochemical lycopene more available. Cooking also enhances the availability of carotenoids, phytochemicals found in carrots, broccoli, and red peppers.

Some cooking methods do a better job at preserving important nutrients. Minimal water and duration of heat matter.

Steaming. This moist cooking method allows vegetables to get crisp-tender quickly and delicately. Compare steaming to boiling in water to cover, which causes some loss of water-soluble nutrients like vitamins C and B. 

Best to cut into uniform pieces to ensure even cooking. Steaming in minimal water is easy in the microwave or in a steamer basket placed in a pot. The steaming water can be flavored with herbs, garlic, lemon, etc. 

I prefer to microwave in an inexpensive Pyrex bowl or dish with a lid. Some frozen vegetables, like peas and corn, may not even need water.

A micro-steaming method from The Food Lab, Better Home Cooking Through Science: “Lay vegetables in a single layer on a microwave plate. Cover with a triple layer of damp paper towels.  Microwave on high heat until the vegetables are tender, 2-1/2 to 6 minutes, depending on the power of your microwave.”  Vegetable-specific prep instructions are provided.

Stir-frying.  This very fast method using high heat and oil is perfect for quick meals. The ideal pan is a flat-bottom wok for max exposure of the vegetables to heat, but a skillet with high sides works to contain the vegetables. 

Have the vegetables cut into uniform bite-size pieces ready to throw in the pan. Preheat the pan before adding oil. Use just enough oil to form a thin film on the pan. Once the oil is hot, add vegetables. 

Oil’s smoke point is important here. It’s that temperature at which oil begins to burn and smoke. This gives food a burnt, bitter taste. Stir frying requires an oil with a higher smoke point.

Although extra virgin olive oil is a feature of the Mediterranean way of eating, it’s not desirable for stir frying due to its lower smoke point.  Canola, corn, soybean, avocado, and peanut oils have a higher smoke point.

For interesting flavor, consider peanut oil for a nutty flavor or sesame oil.  Sesame oil, though, needs to be lightly drizzled on towards the end of cooking, which is my preference after cooking in neutral-flavored canola oil.

Roasting. Like stir frying, roasting requires high heat and oil. Again, cut into bite-size, uniform pieces. Add enough oil to give a glossy coating, but not puddle in the bowl. One to two tablespoon can be enough. It’s easy to cover all the surfaces tossing with your hands. 

Spread the vegetables on a large enough sheet pan to allow each piece some space.  Roast until pieces become fork tender. A rule-of-thumb: roast until toast. The charred tips and edges give roasted vegetables wonderful flavor. 

Roasting time depends on the vegetable and piece size.  All, though, will need to start in a preheated 425-degree oven. 

A vegetable roasting resource:

About Mary Lynne Hixson, MA, RD:

Mary Lynne, a registered dietitian, helps others enhance their health through the advocacy of nutrient-rich food choices and safe food-handling practices. Her expertise also includes counseling patients who have Type 2 diabetes and advising those who are in medically managed weight loss programs. After her 35+ year career, she retired and became involved with the launch of Harvest of Hope Pantry in 2012 as a Board of Directors member. Mary Lynne is a weekly volunteer with Cultivate’s Carry-Out Caravan program, shopping and delivering groceries to seniors in the Boulder area, and also a frequent volunteer with Harvest of Hope.