1. Gently heat the oil and add the mustard seeds, black pepper and turmeric.
2. Once they start popping add the red chilli, garlic and shallots.
3. Add the tomato, cumin powder and a little sprinkling of water.
4. Saute for a few minutes before stirring in the spinach, watercress and rocket, in batches, until it is all wilted. Sometimes I like to add a small knob of butter to intensify the flavour.
5. Season with salt and finally squeeze in a little lemon juice.