Cut the rump steak across the grain into thin strips. Deseed the pepper and cut it into strips, and slice the onion into half rings.
Heat the olive oil in a large frying pan until very hot. Sear the beef briefly over a high heat until coloured on the outside, then take it out of the pan.
Reduce the heat a little and fry the onion and pepper in the pan until both are lightly browned but still have some bite.
Add the soy sauce, mustard and a little water to the pan and stir briefly. Let the sauce reduce slightly so it coats the veg.
Return the seared beef and its juices to the pan. Toss briefly and season to taste with sea salt and black pepper. In pregnancy, cook the meat through until it is no longer pink.
Serve immediately, while the meat is still tender and the pepper slightly crunchy.
Good to know
A dish like this is on the table fast and still feels properly rounded. Juicy, full of flavour and without much effort. On long days especially, it's worth its weight in gold.
Swaps
Rump steak → turkey breast (similar protein content). Soy sauce → tamari (usually wheat-free – check the gluten-free label; a little milder). Mustard → Dijon mustard without added sugar (a sharper flavour). Olive oil → ghee (very heat-stable, full-bodied; contains milk).
Allergens
Contains soya, gluten (wheat in the soy sauce) and mustard. For children, keep the sauce mildly salted; in pregnancy, the dish is fine as long as the beef is cooked right through – heat the strips through again until no longer pink when you return them to the pan.
