Cook carrots and turnips in a large saucepan of boiling salted water over high heat until just tender (2-3 minutes), drain and set aside.
Heat butter in a large frying pan, add carrots, turnips and sugar, sauté over medium-high heat until golden (1-2 minutes). Season to taste, cover, reduce heat to low, cook until vegetables are tender (2-3 minutes). Add stock, increase heat to high and cook, shaking pan, until liquid is reduced to a glaze (4-5 minutes). Stir through parsley, season to taste, serve with squab braised with juniper.