Start by cutting the beef steak into thick strips then into cubes.
Cut the onions into half-moon slices.
In a skillet, add all the meat cubes and top them with the onion slices.
Add the unsalted butter, the water, cover the skillet, turn the heat at medium power and let it all cook for 1 hour.
After this indicated time, uncover the skillet and stir very well.
Add the salt, the black pepper, the garlic cloves chopped into small cubes, stir well.
Cover the skillet again and let it all cook for another 15 minutes.
Finish with parsley to taste.
Serve.