Chop up your paneer into cubes and pop it in the freezer for 15 mins.
Combine your plain flour, cornflour, ground cumin, five-spice powder, turmeric, chilli powder and 1 tsp salt in a bowl. Toss the paneer in 1 tbsp of oil and then coat in the flour mixture.
Heat up a large saucepan with an inch of oil and shallow-fry the paneer until golden brown, about 2-3 mins per side. Remove to a plate lined with a paper towel and keep aside.
Chop up your onion and pepper into large chunks and finely slice your spring onions.
Pound the Sichuan peppercorns in a mortar and pestle until fine. Then add the ginger, garlic and green chillies and pound to form a thick paste.
In a bowl combine the soy sauce, ketchup, sriracha and vinegar.
Heat up a few glugs of oil in a large pan. Once hot, add in the garlic paste and sauté for 1 min until fragrant. Add the onions and peppers and cook until soft for 3 mins.
Pour in your sauce and bring it to a bubble. Add in the paneer and mix well. Cook for 3 minutes until it’s heated through and slightly softened.
Sprinkle with the spring onions and serve.