Preheat oven to 400F.
Prepare your sweet potato: Toss cubed sweet potato with maple syrup, cumin, smoked paprika, garlic powder, and salt. Spread onto a baking sheet lined with a silicone baking mat or parchment paper.
Prepare your peppers and onions: Check to make sure that your onion strips and bell pepper strips are approximately similar in length so that they will all cook mostly evenly (If one is significantly longer than the other, chop the long one in half so that they are closer in length). Toss the strips of peppers and onions with lime juice. Spread onto a second baking sheet lined with a silicone baking mat or parchment paper. (It's important that the sweet potato is on a different baking sheet than the peppers and onions because they typically don't all need the same length of time to cook).
Roast your sweet potato, and your peppers & onions: Place both baking sheets in the preheated oven. Allow both to bake for 12 minutes. Remove from oven, flip the contents of each tray, and return to the oven for another 8 minutes. Remove from oven, give one more flip, and then return to oven and allow to roast until they are cooked to your liking. (I usually end up giving the sweet potatoes about 12 more minutes and the peppers & onions about 8 more minutes). Your sweet potatoes should be fork tender and your peppers and onions will likely have just a little bit of charring. While both of these are roasting, you can work on steps 5 & 6.
Toast your corn and pumpkin seeds: Bring a medium/large nonstick pan to medium heat on the stovetop. Add your corn to the pan. Stirring once a minute, allow your corn to toast on the stovetop for about 5 minutes. (If you have any issues with the corn sticking to the pan you can stir a bit more often. But be sure to let the corn sit, untouched, in between stirs or it won't get toasty). Continuing to stir once a minute, add the pumpkin seeds to the pan and allow to toast with the corn for 6 more minutes (or until toasted to your liking). Remove from heat.
Make your Chipotle Sauce: Remove one chipotle pepper from the can of chipotle peppers in adobo sauce. Use a knife to remove and discard the stem from the pepper (if there is one). Slice open the chipotle pepper lengthwise, and carefully scrape out and discard the seeds. To a high powered blender (using a small blender cup if you have it), add the seedless pepper, 1 teaspoon of adobo sauce from the can, coconut yogurt, maple syrup, cumin, lime juice, and garlic. Blend until super smooth.
Assemble your tacos: To each tortilla add a handful of the roasted peppers & onions, a few scoops of the roasted sweet potatoes, a generous sprinkle of the toasted corn & pumpkin seeds, a couple slices of avocado (if using), and either a drizzle or a larger dollop of the chipotle sauce (depending on your spice preference). Enjoy!