Chop the onion, the mushroom, the tomato and the beef fillet into small pieces.

Saute the mushroom and the onion into a large skillet on high heat. When done add the tomato pieces and stir for about a minute and then lower the heat.

At the same time on another skillet saute the beef until no longer pink. Then add the honey and stir for about a minute and then add some water. Keep stirring until the water is gone at which point add the mustard and again some more water. Lower the heat and let it boil in the water you just added for 5 minutes.

When all is done it's time to mix the contents of the two skillets into one. Add the oil, pepper and salt, pour some extra water if needed and let it cook on low heat for 10 minutes.