Caldo verde is a mainstay of northern Portugual's culinary traditions. Roughly translated as "hot green," it is a warming soup of simmered and mashed potatoes, sliced garlic sausages and a chiffonade of emerald kale, seasoned with locally pressed olive oil and a dusting of black pepper. Served with a loaf of broa (yeast-risen corn bread), caldo verde provides a soothing antidote to sodden and chilling winter evenings.

In the rugged mountain villages of northern Portugal, in tidy little farm gardens bordered with stone fences, nearly every farm wife raises a stand of kale and a patch of potatoes to see her family through the winter. She also has a spiky stand of maize (a short-stemmed corn) from which she produces meal for making bread. The potatoes are dug in the autumn and packed away in straw in root cellars, but the kale is left throughout the winter to stand where it grows and be cut fresh when needed.

As avid vegetable gardeners will tell you, a few vegetables (including kale, parsnips and brussels sprouts) don't really come into their own until they have been nipped by frost. Kale that has stood through a night under a heavy mantle of ice only to be thawed in the midday sun and refrozen the next night develops a depth of character and sweetness that can't be duplicated.

It is from these earthy basics, along with linguic,a (a spicy Portuguese pork-and-garlic sausage), that a warming Portuguese winter meal evolves. If linguic,a is not available, substitute Spanish chorizo sausage or another garlic sausage. Chunks of good quality ham or Canadian bacon can be used as well. CALDO VERDE (Kale and Potato Soup with Sausages) (8 main course servings)

This warming soup, with its spicy aroma of garlicky, smoked pork sausage and fragrant olive oil, is a hearty and welcome invitation to the winter supper table. Accompanied by a fresh warm loaf of broa, as it is in Portugal, and perhaps a salad of fresh greens, it makes a very satisfying meal in itself.

To reduce the olive oil (and thus the fat content) in this soup, but still retain its very desirable flavor contribution, try adding only 2 tablespoons to the pot of soup. Then when the soup is served, pass a cruet of olive oil for diners to sprinkle on their steaming bowlfuls as they wish.

1 pound fresh kale, thoroughly washed and drained

2 pounds potatoes, peeled and sliced

10 cups water

1/2 pound linguic,a, chorizo or other smoked, garlic-flavored pork sausage

1/2 cup extra virgin olive oil

Salt to taste, about 2 to 3 teaspoons

Scant 1/2 teaspoon freshly ground black pepper

Tear the kale leaves from their stems and arrange in stacks. Firmly roll up a stack, and with a sharp knife cut the roll crosswise into paper-thin slices. Repeat with remaining leaves.

Place the potatoes in the water and bring to a boil. Reduce heat to medium low and simmer, covered, until very tender, about 15 minutes.

Meanwhile, place sausage in a skillet and cover with water. Heat to a boil, reduce heat to low and simmer, covered, about 15 minutes. Drain and cut in thin slices.

With a slotted spoon remove the potatoes from their cooking liquid and mash them until smooth. Return the mashed potatoes to the hot liquid and add the olive oil, salt and pepper to taste. Stir in the shredded kale and, stirring frequently, bring to a boil. Boil 3 minutes, stir in the sausage slices and heat through. Correct seasonings and serve immediately with a basket of hot broa. BROA (Yeast Corn Bread) (Makes two 9-inch round loaves)

For added nutrition and flavor, I often substitute 1/2 cup of wheat germ for 1/2 cup of the all-purpose flour in the first 2 cups of flour used and proceed with the recipe as usual.

2 ( 1/4-ounce) packages active dry yeast

2 teaspoons sugar

1/2 cup lukewarm water

3 cups yellow cornmeal

Scant tablespoon salt

2 cups boiling water

2 tablespoons plus 2 teaspoons extra virgin olive oil

3 1/2 to 4 cups flour

In a small bowl, combine the yeast, sugar and warm water and allow it to stand in a warm place until it doubles in volume.

Meanwhile, pulverize the cornmeal, 1 cup at a time, in a blender until very fine. In a large mixing bowl, combine 2 cups of the cornmeal, the salt and the boiling water and stir until smooth. Stir in 2 tablespoons olive oil and set aside to cool.

When the cornmeal mixture has cooled to lukewarm, stir in the yeast mixture, the remaining 1 cup of cornmeal and about 2 cups of the flour; press the dough into a ball in the bowl, drape it with a towel and set it in a warm place until it doubles in bulk, about 1/2 hour.

Turn the risen dough out on a floured counter and vigorously knead in as much of the remaining flour as it will take to make a firm, but not stiff, dough. Divide the dough in half and shape into 2 balls.

With the remaining olive oil, grease 2 pie plates, put the balls of dough in the plates, cover with a towel and allow to rise again in a warm place until doubled in bulk.

Bake loaves in a 350-degree oven about 40 minutes, until golden. Remove from pans and cool on racks at least 20 minutes before slicing. Serve warm with unsalted butter. Adapted from "Foods of the World, Spain and Portugal" (Time-Life books, New York)