Christmas at the Stewart's: a festive open house, a quiet family dinner

''Entertaining always seemed natural to me,'' says Martha Stewart, ''a matter of taking something very appealing to me - a favorite dish, a holiday, an activity - and making it bigger, to include others. ''

At Christmas, once the Stewart's house is decorated and a warming fire is lighted in the fireplace, Martha and her husband, Andy, invite friends to a festive, but informal, afternoon open house.

As she describes the occasion in her book: ''The dining-room table is decked with holiday desserts. Down the hall in the parlor, eggnog froths in a silver bowl. Next door the library table is set for tea, around a centerpiece of croquembouche.

''And the kitchen is ready for children: mulled cider on the stove, sugar cookies and chocolate chip cookies mounded on platters.''

Martha's recipes, which emphasize fresh, simple, homespun food, fit in perfectly with this festive, busy season.

Food, to Martha, is an adventure to be shared - from her original, and at times, exotic hors d'oeuvres, such as snow peas stuffed with boursin cheese, chili in corn cups, smoked turkey on blueberry scones - to her traditional and beautiful desserts, glistening cranberry tartlets in crunchy walnut crusts, pumpkin pie with a touch of molasses, and a mincemeat tart with a lattice top.

After the merriment of the open house, the Stewarts celebrate a quiet Christmas Eve and Christmas Day with their daughter, Alexis.

For several years they have had the same traditional Christmas Eve dinner - champignons (mushrooms) under glass, parsleyed baby rack of lamb, gratin of potatoes, endive and watercress salad, and a baby croquemboche for dessert. After dinner they decorate their tree, and make a few quick trips to neighbors to distribute packages.

''Making edible presents for friends and neighbors is one of the nicest ways to get in the mood for Christmas,'' says Martha. Some of her favorite gifts are traditional fruitcakes and plum puddings, crab apple and red pepper jellies, and vinegars flavored with sprigs of tarragon, mint, or basil, or a handful of berries, including raspberries, blueberries, and blackberries.

Christmas Day brings a dinner of delicious surprises - a creamy mussel soup, crown roast of pork, decked with paper frills and filled with a wild rice and prune stuffing, a spicy quince preserve made with fruit from the Stewart's own trees, and plum pudding, set on a silver platter surrounded with fresh holly.

Here are two of Martha's recipes that provide a small, delicious taste of something before a special holiday dinner.

Since guests are more adventurous with one biteful than with a whole plateful of something new, hors d'oeuvres give the hostess the freedom to be creative with unusual foods and combinations of foods, as long as they are all very fresh and beautifully arranged. Gingersnaps With Chutney Cream Cheese 1/4 cup dark brown sugar 1/3 cup molasses 1/4 cup unsalted butter, softened to room temperature 1 egg 1 teaspoon baking soda 1/4 teaspoon salt 1/4 teaspoon ground allspice 1/2 teaspoon ground cinnamon 1/4 teaspoon ground cloves 1/2 teaspoon ground ginger 2 1/4 cups flour 1 8-ounce package cream cheese, softened to room temperature 1/4 cup finely chopped mango chutney

To make gingersnaps, cream sugar, molasses, and butter in large mixing bowl. Add egg and beat until fluffy.

Sift into another bowl the baking soda, salt, allspice, cinnamon, cloves, ginger, and 3/4 cup flour. Add all at once to molasses mixture and beat until are just mixed. Stir in remaining 1 1/2 cups flour and beat to form a stiff dough.

Divide dough into 1 cup amounts, flatten portions, and wrap each in plastic wrap. Refrigerate for at least 2 hours, preferably overnight.

Preheat oven to 350 degrees F. Lightly butter 2 large baking sheets. On a lightly floured surface, roll out dough about 1/8-inch thick.

With crimped pastry wheel, cut dough into 1-by-2-inch rectangles. Put on baking sheets and then, prick with a fork in an even pattern.

Bake until crisp, about 10 minutes. Cool completely on wire racks.

Mix cream cheese with chutney and serve with gingersnaps. Makes about 70. Baked Country Ham on Blueberry Scones 2 cups flour 1/2 teaspoon salt 2 teaspoons baking powder 1/4 teaspoon baking soda 1/4 cup butter 1/2 cup buttermilk 1 tablespoon molasses 1 cup fresh or dry-frozen blueberries 1/2 pound thinly sliced baked ham

Preheat oven to 425 degrees F. and lightly butter a baking sheet. In large bowl, sift together flour, salt, baking powder, and baking soda.

Cut butter into dry ingredients with pastry cutter until mixture resembles coarse meal. Mix buttermilk with molasses and add to flour mixture; stir in blueberries.

Work mixture gently and quickly with your hands until it holds together; dough should be crumbly.

Pat dough out to 1/2-inch thickness on lightly floured board. With 3-inch floured biscuit cutter, cut out as many rounds of dough as possible.

Pat out scraps to make as many more rounds as possible. With a sharp knife, cut each round into 4 triangular quarters. Transfer to baking sheet and bake in center of oven for 8 to 10 minutes, or until golden brown and puffed. Watch carefully to prevent overbaking.

Cut ham into triangles slightly larger than scones. Using a sharp slicing knife, split scones and fill each with 1 or 2 triangles of ham to make little sandwiches. Makes about 36.

To make larger quantities of scones, repeat recipe. Slivers of smoked turkey are also delicious on blueberry scones. Mulled Cider 1 gallon cider 8 3-inch cinnamon sticks 4 apples, studded with cloves 10 whole allspice Combine ingredients and simmer for 30 minutes. Serve hot from a large earthenware bowl and ladle into cups. Makes approximately 32 servings.