“This is a study in progress,” Drewnowski said. “But in at least one case, the person was a recent Asian immigrant who was going to the market and getting fresh produce and going back home and cooking it. In this case he had the knowledge and the cooking skills that are essential.”

Carlson further suggests that Americans could benefit from spending a larger percentage of their food budget on fruits and vegetables. The correct number is about 40 percent, she estimates, more than most of us spend.

And as if we need more proof that cooking is important, Drewnowski said he is in the early stages of yet another study that so far indicates: “The more time you spend in the kitchen, the better your overall diet quality.”

Discussions of the best options for cheap, tasty nutritious meals often boil down to three words: rice and beans. Depending on how you prepare the combo, it can be dull and boring or downright delicious.

As a child I looked forward to my Puerto Rican grandmother’s rice and beans as a Monday delicacy, and my kids love Nana’s rice and beans, flavored with a sofrito (diced sautéed vegetables), just as much.

The rice

• Heat 4 cups water to a boil in a kettle.

• Meanwhile, cook 2 cups rice (preferably brown) and 1/2 teaspoon salt with 1 tablespoon olive oil in a saucepan over medium heat, stirring to coat the rice with the fat.

• Pour the water over the rice. Let the water boil down until you can see the surface of the rice.

• Cover; turn to a very low flame. Simmer until the rice is tender.

The beans

• Cover 3 cups dried beans with 2 inches water in a bowl or stockpot. Soak overnight.

• Drain the soaking water from the beans.

• Place the beans in a big pot; fill with water to cover beans by 1 inch.

• Heat to a simmer; simmer until soft, 1 hour or more.

• Wait until beans are tender before adding 1 teaspoon salt. Taste for seasoning.

• Meanwhile, heat 1 tablespoon olive oil in a heavy-bottomed saucepan.

• Add 1/2 green pepper, finely diced; 1/2 onion, finely diced, and 3 cloves garlic, minced. Season with a pinch of salt.

• Cook until fragrant and tender.

• Stir in 1/4 cup cilantro; cook until herb gives off its aroma.

• Add half a can (from an 8-ounce can) tomato sauce; cook to meld flavors.

• Drain the cooked beans, saving 1 cup cooking water; pour beans into the sofrito mixture.

• Add reserved cooking water; heat to a boil, then turn down to a simmer. Salt to taste.

• You also can add half packet of Sazon Goya seasoning blend and/or 1/4 cup chunks cooked winter squash for extra flavor and texture.

• Serve over the rice with a nice green salad. Makes 6 servings.

Cost breakdown

Rice: 92 cents

Beans: $2

Olive oil: 60 cents

Green pepper: 40 cents

Onion: 50 cents

Garlic: 20 cents

Cilantro: 12 cents

Tomato sauce: 45 cents

Total: $5.19

Cost per serving: 87 cents