Steak and Veg Stir-Fry

500 g rump steak or scotch fillet trimmed, sliced into strips

2 tablespoons olive oil

1 brown onion, sliced

2 carrots, sliced

2 red capsicum, diced

1 bunch broccolini, chopped

2 tbsp oyster sauce

2 tbsp kecap manus

Steamed rice, sliced spring onions and lemon wedges, to serve