Peel and chop the shallots. Season the steaks. Fry them in butter and oil. Set aside and keep warm.
To deglaze the cooking juices: add the shallots with a small knob of butter and stir with a wooden spatula. Add the red wine, a pinch of sugar and let it boil until the sauce reduces by three quarters.
Add the remaining butter, whisking. Check the seasoning. Pour the sauce over the steaks. Sprinkle with chopped parsley.