1. Warm the olive oil in a deep frying pan and brown the beef stripes all over for 5-6 minutes until the meat is cooked through. Pour the balsamic vinegar in, wait for the alcohol to evaporate, then, add the mustard, honey and garlic and stir everything well. Sprinkle with the thyme and season to taste.
2. Chop the leafy vegetables finely and place them in a salad bowl. Add the beef with its sauce and scatter the pine seeds over. Combine everything well and serve.