Frozen vegetables are distinct from fresh ones for two reasons:

The first is that almost all frozen vegetables are blanched (briefly boiled) before being frozen. Blanching denatures enzymes in the vegetables that can alter color, flavor, and texture if left intact.

Second, the freezing process (even very quick freezing as is done commercially) creates ice crystals that damage cell walls in plants. If you thaw them out, they will purge a watery solution. What you want is to cook them in a way that evaporates excess water while retaining the flavor compounds and nutrients in the liquid.

Microwaving is a bad idea for a number of reasons. What you want to do is use quick, high heat to cook them. There are two good ways to do this.

Oven Method

The first technique is on a sheet pan in the oven. This is great for broccoli, Brussels sprouts, and cauliflower. Put your sheet pan into the oven and preheat the oven to 425–450°F. This way the pan will be very hot when you add the vegetables. Browning the vegetables (Maillard browning) will add flavor and improve the texture.

They should be cooked from frozen, not thawed first. A digital thermometer is not necessary. You would use the thermometer for cooking meat for food safety or for cooking sugar when trying to reach a particular temperature (you’ll learn about this in the sugars and starches module). Thermometers are also useful for other tasks such as checking the doneness of bread and cakes.

Depending on your portion size, add a little extra-virgin olive oil (EVOO) — maybe one tablespoon for 12 ounces of vegetables. This is a healthful oil, and it will be fine in the oven. I understand you’re trying to watch your calories, but the quality of the calories you do eat is often more important than the number of calories. The oil will allow the vegetables to cook much better, browning more completely and more evenly. Sprinkle some kosher salt on top either after they’re on the sheet pan or while you’re coating them in a thin layer of oil.

Stove-Top Method

For green beans, asparagus, or mixed medleys, cook the vegetables in a wide skillet (such as stainless steel or cast iron). The surface area is important so steam can escape easily. You want to heat via conduction, not steam. Season them like above.

Heat the pan on medium heat until it’s around 400°F (you can test this with the Leidenfrost test which we’ll learn about in class). Don’t add the oil until the pan is fully at temp. (Adding it early just breaks down the oil, which is worse for flavor and worse for health). As soon as you put the oil in it will come to temperature immediately, so add the frozen vegetables right away and start stirring them as soon as they hit the pan so they don’t stick.

They will start sizzling as soon as they hit the pan. Once they’ve cooked for about a minute you can stop stirring and let them sit until the sizzling dies down. Continue stirring occasionally so they brown evenly.

Seasoning

In addition to salt, adding glutamates will make a huge difference in flavor. For example, Brussels sprouts are a little bitter, but glutamates cut bitterness by about 70% in addition to increasing umami flavor. You can use soy sauce, tamari, or MSG. Or, grated Parmigiano Reggiano. Or mushrooms (especially dried shiitake mushrooms, ground into a flour), which will add a huge amount of umami.

A squeeze of lemon juice will brighten the dish and “wake up” the flavor. Other things you can add are garlic and/or onion powder, smoked paprika, or cumin. Add those to the oil so they infuse during cooking.

Good luck and let me know how it turns out!

Chef Michael