1. Heat wok or large skillet over medium heat. Add 1 1/2 teaspoons oil; cook polenta, turning halfway through, 3 minutes. Transfer to platter; cover.
2. Add remaining 1 1/2 teaspoons oil to wok; cook turkey 3 minutes. Add lemon juice, 1/2 cup broth, 1 garlic clove, and currants. Cook, stirring, 1 minute more or until turkey is cooked through. Transfer to platter with slotted spoon, reserving liquid in wok; cover.
3. Add Swiss chard and onion to wok; cook, stirring, 3 minutes or until tender. Add remaining 1/2 cup broth and garlic; cook, stirring, 2 minutes more.
4. Spoon the chard mixture onto a platter; top with pine nuts.