After chopping the potatoes and cauliflower, transfer each vegetable to its own bowl of hot water for 5 minutes or so while you prep the onion, garlic and ginger, and, in a small bowl, combine the ground spices – ground cumin, coriander, turmeric, garam masala, and red chilli powder; not the cumin seeds nor amchur.
Just before you’re ready to begin cooking, drain the vegetables in a colander, pat them dry with a paper kitchen towel, and set them aside.
In a round flat-bottomed wok over medium-high, heat the oil until shimmering, add the cumin seeds and when they start to sizzle, add the minced garlic and ginger and stir-fry until fragrant, then add the diced onion, stir-fry for a few minutes until soft, aromatic and transparent, and finally add the finely diced tomato and stir-fry until soft.
Add the mixed ground spices, stir to combine, fry the spices, and if needed (if too dry), deglaze the wok with 2-3 tablespoons of water, then add the potatoes, stir-fry for a few minutes, then add the cauliflower and sliced green chillies, combine, and continue to stir-fry for another 5 minutes.
Reduce the heat to low, cover the wok, and cook the aloo gobi for around 20-25 minutes, keeping an eye on it, and stirring it every 5 minutes or so. Remove the lid, use a fork to check how tender the potatoes are; if they’re starting to soften, stir the aloo gobi, increase the heat to medium and leave the lid off to reduce any remaining liquid so you have a dry curry of soft vegetables.
When ready, season with the optional salt to suit your palate if needed, sprinkle on the amchur or lemon juice and dried fenugreek, stir through the aloo gobi, transfer to a serving bowl, and garnish with fresh coriander leaves.
Serve your aloo gobi as a side with an array of dishes if preparing an Indian feast or if eating alone, serve with rice or Indian flatbreads such as naan or roti, or with papadams as a snack.