First make the sauce. Heat the oil or ghee in a pan, add the garlic and let it colour. Stir, then add the coriander seeds and red chillies.
When they release their aromas add the onions and cook until starting to turn light golden. Stir in the ginger, green chillies and tomatoes.
Reduce the heat to low and cook until all the excess moisture has evaporated and the fat has started to separate out. Add the salt, garam masala and fenugreek leaves and stir. Taste and add some sugar if needed.
For the stir fry heat the oil or ghee in a wok or large frying pan. Add the crushed chillies, pepper strips and red onion. Stir and saute on a high heat for under a minute, then add the paneer and stir for another minute.
Add the sauce and mix well. Once everything is heated through check seasoning and finish with the fresh coriander, fenugreek leaves and lemon juice.