2) Drain the beans and rinse under tap water, then add to the pan and warm through, stirring and squishing with a wide, flat spoon so that the beans go into a nubbly mush. Season, to taste. Some beans are saltier than others.
3) Meanwhile, heat a tsp of the remaining oil in a large frying pan or skillet and cook the steaks on high for about 1 1/2 minutes a side. Remove to warmed plates, sprinkling some salt, to taste, over them as you do so.
4) Squeeze the lemon juice into the hot pan and let it bubble up with the meaty oil. Pour the sauce over the steaks, serve immediately with the mash.