Preheat oven to 500°F with a pizza stone inside. Heat 2 teaspoons olive oil in a large non-stick skillet over medium heat. When the oil is hot, add the sliced onions and fennel to the pan; season with the salt. Cook onions and fennel 3-4 minutes, until they start to look tender. Add grapefruit juice 1/4 cup at a time, adding additional when liquid is almost absorbed; continue cooking until onions and fennel are very tender and slightly browned, about 15 minutes total. Remove the pan from the heat and stir in chili paste and butter; let it cool slightly while preparing the crust. Spread a handful of Maseca onto a pizza peel (or spread onto a round pizza pan if not using a stone). Gently press, stretch or roll the dough into a 12-14 inch circle. Spread the onions and fennel in an even layer over the dough all the way to the edges. Top onions and fennel with both of the cheeses. Scatter the rosemary and prosciutto over the cheese. Cut away peel and pith of grapefruit. Over a bowl, use a paring knife and slice between membranes to release segments. Scatter the segments over the pizza (chop up smaller, if desired). Bake the pizza in the preheated oven for 12 minutes or until crust is golden and cheese is bubbly. Garnish the pizza with the reserved fennel fronds before cutting into wedges to serve. Makes 6 servings. 2016 Ocean Spray® "Surprisingly Versatile" Grapefruit Recipe Contest Entrant, Veronica Callaghan Per Serving: Calories 430 Total Fat 18g (28% DV) Sat Fat 8g (40% DV) Trans Fat 0g Sodium 1440mg (60% DV) Carbohydrates 46g (15% DV) Dietary Fiber 3g (12% DV) Sugars 8g Protein 22g