A pleasant collection of modish (though not gimmicky) recipes, by two of the 80 zillion California chefs who have discovered red and yellow sweet peppers, radicchio, dried porcini, mussels, fennel, carpaccio, and a lot of ""in"" culinary talismans. The bulk of the recipes are for what most people would consider summery fare, and something of a fuss is made of serving them cold or at room temperature. Butternut squash soup with apples, grated carrot and celery salad with a Gorgonzola dressing, ""gravlax all'italiana"" (fennel and mint instead of dill), cold beef brisket with a tart dressing, and tea granita served with cognac-steeped peaches are all perfectly nice today's-hemline ideas--but one doesn't sense any great sureness of touch, deep grasp of tradition, or original flair. Desserts--not a large selection, but blessed with simple piquancy--strike the most convincing note here.