Make Quick Pickled Red Onions: Place thinly sliced onions in a small bowl or glass jar with the vinegar, sugar and salt. Bring some water to a boil then pour over onions until submerged. Stir onions and ensure they are submerged in the pickling liquid. Set aside to pickle. Store extra pickled red onions in a jar in the fridge.
Make Avocado Sauce: In a small food processor or blender, add avocado, lime juice, lime zest, garlic, cilantro and water. Season with salt and pepper. Blend until smooth.
Prepare for Tofu: Heat a large skillet over medium-high heat. While the pan heats, pat the block of tofu dry and use your hands to crumble tofu into small pieces in a bowl. In a separate small dish, add the spices and tomato paste so they're ready.
Toast Spices: When the pan is hot, add 1 tbsp oil. Then add chili powder, cumin, smoked paprika, garlic powder, onion powder and tomato paste. Cook for 45 sec-1 min, stirring constantly, to toast spices.
Cook Tofu: Add tofu crumbles and ¼ cup water. Spread in an even layer and cook for 5-7 min, stirring occasionally, until golden brown. Remove the pan from the heat. Stir in soy sauce or tamari.
Serving: Divide the tofu taco filling between warm tortillas. Top with shredded cabbage and tomatoes, if desired. Dollop with avocado sauce and top with pickled red onions and more cilantro. Serve with lime wedges.