Beef and mushroom stroganoff

Ingredients (serve 4): 500g lean beef stir-fry strips 1 tsp sweet paprika 1 tbs olive oil 1 onion, thinly sliced 250g button mushrooms, halved 1 cup (250ml) salt-reduced beef stock 1 tbs Worcestershire sauce 3/4 cup (180g) light sour cream 200g green beans, topped 2 tbs chopped chives 4 slices wholegrain toast, to serve (optional)…