Step 1Remove sausage from casing and roughly crumble into medium skillet. Fry over medium heat until cooked, about 5 minutes. Drain on paper towels.
Step 2In small dry skillet, lightly toast pine nuts over low heat, shaking frequently.
Step 3Heat oil over medium-high heat in large skillet. Add garlic and cook until softened, 1 to 2 minutes. Add Swiss chard and saute until just wilted, stirring frequently, about 3 minutes. Remove from heat and add pine nuts and sausage; stir to combine.
Step 4Combine fontina and mozzarella cheeses.
Step 5Place pizza shell on heated baking sheet. Brush outer 3/4 inch with oil, then scatter half of combined cheeses over center, leaving a 3/4-inch edge. Evenly distribute sausage mixture over cheese, then top with remaining cheese. Bake at 450 degrees until cheese is melted and bubbly, 8 to 10 minutes.