Place veal in a medium bowl with paprika and toss to coat. Lightly spray a large non-stick frying pan with oil and heat over medium-high heat. Cook veal, in batches, for 2 minutes or until browned all over. Transfer to a bowl.
Cook onion and garlic in same pan, stirring, for 3–4 minutes or until softened. Add mushrooms and cook, stirring, for 2 minutes. Return veal to the pan with stock, tomato paste and Worcestershire sauce. Bring to the boil. Reduce heat and simmer, uncovered, for 5 minutes.
Meanwhile, cook pasta in a large saucepan of boiling salted water, following packet instructions, or until just tender. Drain.
Add sour cream to veal mixture. Stir until heated through. Divide pasta among serving plates. Top with stroganoff and sprinkle with chives. Serve.