Mix together the light and dark soy sauce, vegetable oil and black pepper either in a plastic bag or bowl. Add the steak and allow it to marinate for at least 20 minutes.
Mash the garlic clove for the dressing.
Chop the chilli pepper as finely as you can.
Mix the garlic clove and diced chilli with the remaining ingredients for the dressing.
Heat a 28cm or 11" skillet or frying pan (not nonstick if possible) over a high heat.When the skillet is smoking hot, cook the steak to your liking. My steak was between 1½cm and 2cm (½-¾") thick and was cooked for no more than 2 minutes (closer to 90 seconds to be this rare) per side.Then rest your steak for 10 minutes under foil.
Cut the cherry tomatoes in half.
Cut the ends off the cucumber and then cut it in half lengthways and finally into thin strips 2-3mm (⅛") thick.
Peel the shallot and then cut it in half lengthways and finally into half-moon shapes as finely as you can.
Slice the celery across the rib into thin slivers approximately 2-3mm (⅛") thick.
Slice the spring onions at a 45° angle approximately 2-3mm (⅛") thick.
Roughly chop the mint and coriander and place them in a bowl.
Add the chopped vegetables to the bowl with the herbs and mix well.
Dress the remaining salad ingredients with some of the dressing.
Finely slice the beef and add it to the salad, mix it all well and dress your plate.