In large skillet, heat 1 Tbsp oil until shimmering. Add turnips and radishes and cook over moderately high heat, stirring, until lightly browned and crisp-tender, 10 minutes.
Add honey and cook over moderate heat, stirring, until the vegetables are glazed, 5 minutes. Add soy sauce and cook until syrupy, 5 minutes longer.
Add lemon juice and Swiss chard; cook until chard is wilted, 2- 5 minutes. Raise heat to high and cook until all of the liquid has evaporated, 2 minutes longer. Serve .