Preheat the oven to 450°F. Slice the sweet potatoes into ½ inch rounds. On a lined sheet pan, toss the sweet potato rounds with a drizzle of oil; season with ⅓ of the spice blend and S&P. Arrange in a single, even layer and roast in the oven, 22 to 24 minutes, turning over once, until browned and tender when pierced with a fork.
While the sweet potatoes cook, in a medium pot, combine the quinoa (rinse before adding), 1 cup water (double for 4 portions) and a pinch of salt; bring to a boil. Reduce the heat, cover and let simmer, 14 to 16 minutes, until the quinoa is tender; season with ½ the remaining spice blend and S&P to taste. Fluff with a fork and set aside in a warm spot.
While the quinoa cooks, zest and juice the lime. Small-dice the cucumber. Small-dice the radish. In a medium bowl, combine the radish with the cucumber. Roughly chop the lettuce, discarding the root end. Cut off and discard the root end of the scallion; thinly slice, separating the white bottoms and green tops.
To the bowl of cucumber and radish, add as many of the white bottoms of the scallions and as much of the lime juice as you’d like, plus 1 tbsp oil (double for 4 portions). Season with the remaining spice blend and S&P to taste.
To the pot of quinoa, add as much of the lime zest as you’d like; stir to combine. Divide the finished quinoa between your bowls. Top with the roasted sweet potato, cucumber-radish salsa and lettuce. Drizzle as much of the avocado-lime dressing as you’d like over the dish. Garnish with the pepitas and as many of the green tops of the scallion as you’d like. Bon appétit!