Drain the extra-firm tofu. Press it either with a tofu press, or wrap it in a clean kitchen towel and place under a heavy pan or weight for 15 minutes to remove excess water.
Using a mandoline slicer, or the slicer side of a box grater, shave the tofu into very thin irregular strips. It’s 100% alright if some break apart - that’s going to happen a little bit anyway when cooking the tofu.
Warm a large nonstick or well-seasoned skillet over medium-high heat. Add half of the vegan butter. After 90 seconds when the butter is hot, add half of the tofu strips, cooking for a few minutes on both sides to brown them. Remove the first batch of tofu, add the remaining butter and when it has melted, cook the second half of the tofu the same way, until it’s lightly golden all around. Add the first batch of tofu back into the pan.
Meanwhile, place the silken tofu, garlic, onion, plant milk, glutinous rice flour, nutritional yeast, Dijon mustard, chili powder (or paprika), turmeric, asafetida (if using), black salt, and miso paste in a blender. Blend for about 30 seconds on high speed until smooth.
Pour the blended silken tofu mixture into the skillet.
Stir thoroughly to coat the browned tofu sliced completely. Reduce to medium-low heat and cook for 5-6 minutes, stirring and flipping the tofu about occasionally, until it thickens and resembles soft scrambled eggs.
If using optional vegetables, sauté them separately in a second skillet over medium heat just until tender. Fold them into the scramble during the final 2 minutes of cooking.
Taste and adjust seasoning with additional black salt according to your taste. Serve hot, garnished with chives, parsley, or dill if desired.