Stir together flour, yeast, sugar, and salt in a large mixing bowl. Add about half of the warm water. Do not stir. Let stand for 10 minutes. Add remaining water, the olive oil, walnuts, and rosemary. Mix well.
Turn dough out onto a lightly floured surface. Knead for 3 minutes. Shape dough into a ball. Place in a lightly greased bowl, turning once to grease surface. Cover and let rise till double (about 50 minutes).
Grease a 12-inch pizza pan. Place dough on the pan. Use the palms of your hands to pat the dough into an even round, just about to the edges of the pan. Using your fingertips, poke the dough all over to dimple surface. Arrange pear slices and onion slices atop. Drizzle with melted margarine or butter. Sprinkle with Gorgonzola. Cover loosely and let rise for 30 minutes.
Bake in a 400 degree F oven for 25 to 30 minutes or until golden brown. Cut into wedges and serve warm. Makes 12 to 16 servings.