Sauce - Mix cornflour/cornstarch with water until lump free. Add everything else, then mix.

Crumble tofu - Drain tofu, then cut into 5mm/0.2" slices. Use your fingers to crumble into a mince. Not too fine crumbs, can always break up more when cooking (just like cooking mince/ground meat!).

Filling - Heat oil over high heat in a large non stick pan. Cook onion, garlic and carrot for 1 minute. Add green beans and mushrooms. Cook 2 minutes - green beans should still be firm.

Sauce it - Add tofu and toss through. Pour in the sauce. Stir for 1 minute or until the sauce thickens and is coating the mixture nicely. (If it evaporates too quickly, add a splash of water)

Serving - Transfer filling into a bowl. Lay out on the table with lettuce leaves, green onion, peanuts and bottle of sriracha.

DIY lettuce wraps - Spoon filling into lettuce leaf. Drizzle with sriracha, sprinkle with peanuts and green onion. Bundle / fold, eat!