Press Sauté on an electric pressure cooker, adjust to medium,and heat butter and 1 tablespoon oil. Stirin rice and 3/4 teaspoon salt and cook,stirring occasionally, until goldenbrown and toasted, 4 to 6 minutes.Add wine and cook until absorbed, about 1 minute. Stir in broth and sweetpotato; press Cancel. Lock the lidand cook on high pressure (12.5 minutes. Use the quick-releasemethod to release the pressure, thenopen the lid. Stir risotto until liquidhas been absorbed, 2 to 3 minutes.Meanwhile, heat remaining 2 tablespoon oil in a medium skillet onmedium-low. Stir in sage and cook2 minutes, then add garlic andfry, stirring occasionally, until justbeginning to turn golden brown,about 5 minutes. Using a slottedspoon, transfer sage and garlicto a paper towel–lined plate, thentransfer oil into a small bowl andstir in lemon zest.Divide risotto among bowls and top with lemon oil, sage, garlic,and Parmesan if desired.