Rinse and trim squashes, julienne on a mandoline using the skins for a pasta effect or cut into bite-sized chunks or use whole baby squashes.
Heat oil in a large saute pan. Add squash and saute for 1 minute, then in succession tossing and stirring with each addition add beans, corn, tomatoes, then add the sage pesto stirring gently to distribute evenly.
Salt, only if needed and serve immediately.
Toast pine nuts in a dry saute pan or in a 350 degree F oven on a sheet pan. Combine all ingredients in food processor or blender and process until a smooth.