Make the Pickled Red Onion: Boil water then pour into a container large enough to fit the red onion along with the vinegar, salt and sugar. Stir well to dissolve the sugar. Add the red onion, making sure it's all submerged. You can top it off with extra vinegar if needed. Set aside for 30 minutes to "pickle".
Preheat the Oven & Boil Water: Preheat the oven to 400 F and starting bringing two pots of water to a boil on the stovetop.
Cook the Lentils & Quinoa: Cook according to package instructions or see notes for details.
Bake the Tofu: Add the tofu, cayenne, garlic powder, soy sauce and a pinch of salt and pepper to a bowl and toss to coat the tofu. Evenly spread out on a baking tray lined with parchment paper. Bake for 20-25 minutes until browned and crispy.
Bake the Sweet Potato: Add the sliced sweet potato to the bowl you used for the tofu and add 2 tsp of the olive oil, chili flakes, smoked paprika and a pinch of salt and pepper. Toss to coat. Spread the sweet potato on a baking tray and bake with the tofu for 20-30 minutes until tender and browned.
Make the Dressing: Place all ingredients in a small blender and blend until completely smooth. Store in an airtight container until ready to use. The dressing may discolour slightly due to oxidation, this is normal.
Prepare the Kale: Add the chopped kale to a bowl with the remaining 2 tsp of olive oil and the lemon. Massage with your hands for 1-2 minutes until softened.
Assemble the Bowls: Divide the kale between 4 bowls or containers. Top each with 1/4 cup cooked lentils and 1/4 cup quinoa. Divide the sweet potato and tofu between the bowls. Add avocado, pickled red onions and top each with dressing (leave avocado and dressing off until serving if you're making these for meal prep).