To prepare the peppercorns, dry fry them over a low heat for 1–2 minutes until light brown and aromatic. Crush lightly in a mortar and pestle.

Cut the tofu into large cubes and set aside to drain on an absorbent towel.  

Take 100 grams of mushrooms and pulse them in a food processor to a rough "mince." Slice the remaining mushrooms in half.

Place a wok over medium to high heat. Add the oil to heat.

Add the mushrooms and eggplant and stir fry for 1-2 minutes. Add the garlic and ginger and cook for 30 seconds.

Add the the rice wine and the chilli bean paste and cook for 1 minute until the mixture is aromatic.

Add the stock, bring to the boil and season with soy sauce and sugar. Cook for a minute before reducing the heat to a simmer. 

Gently add the tofu and stir carefully trying not to break up the tofu too  much.  Simmer for 6-7 minutes until the sauce has reduced slightly and the eggplant is soft.

Combine the potato starch with 1 tablespoon of water and mix into the sauce. Cook for a further 2 minutes until thickened.

Add the spring onion batons and stir. Remove from heat.

Serve sprinkled with Sichuan pepper, sliced green spring onions and steamed rice.