For the lemongrass marinade
For the stir fry
Make the lemongrass marinade: Place the lemongrass, garlic, soy sauce, neutral oil, sesame oil, sugar, turmeric and crushed red pepper in a large bowl; stir to combine.
Add the tofu cubes to the marinade and toss to coat. Leave the tofu to marinate for 10 minutes. (You can let the tofu marinate, covered, in the fridge for up to 24 hours.)
Heat a wok or large (12-inch) skillet on medium-high for 2 minutes.
Add the onions to the tofu and give them a quick toss so they're coated in the marinade. When the skillet is hot, add the tofu and onions and cook, tossing often, until the onions have softened slightly, about 2 minutes.
Add the broccoli, season well with salt and pepper, and toss.
Reduce heat to medium, cover (a sheet pan works well here) and cook for 2 minutes. Uncover, give it a quick toss and cover again. Cook for 1 minute or until the broccoli is just tender and still bright green.
Top with cilantro or scallions and serve with rice or noodles.
