1. Dough: In bowl, stir together 1/4 cup flour, warm water, yeast and sugar; let stand for 5 to 10 minutes or until mixture starts to look bubbly and frothy. Using wooden spoon, stir in olive oil, remaining flour and salt to make loose dough. Transfer mixture to lightly floured surface; knead for 10 to 15 minutes, adding flour as needed, to make soft, elastic, and slightly sticky dough.
2. Form dough into ball; transfer to lightly greased bowl. Brush top of dough lightly with oil; cover with wet kitchen towel. Let stand in warm spot for about 2 hours or until doubled in size. Punch down dough; transfer to airtight container or resealable plastic bag. Refrigerate overnight; let stand at room temperature for 2 hours.
3. Toppings: Preheat oven to 450ºF. On lightly floured surface, roll out dough into 12-inch round. Transfer to lightly greased 12-inch pizza pan.
4. Spread pizza sauce over dough. Top with mozzarella, salami, red onion and olives. Bake, rotating pan halfway through, for 20 to 25 minutes or until edges are golden brown and cheese is melted. Let cool slightly; sprinkle with green onions.
Tip: Replace soppressata salami with marinated artichoke hearts for a vegetarian option.