Bring 1 cup water to a boil in a small pot. Stir in 1/2 cup quinoa, reduce heat to low, cover, and simmer until water is absorbed, about 20 minutes. Transfer cooked quinoa to a large bowl and let cool.
Preheat oven to 425°F (220°C). Pat the drained chickpeas very dry with paper towels and remove any loose skins. Place chickpeas in a bowl.
Toss the chickpeas with 1 tablespoon olive oil, 1 1/4 teaspoons ground cumin, and 3/4 teaspoon smoked paprika. Spread in a single layer on a large rimmed baking sheet without crowding.
Place the halved, seeded jalapeños in the bowl used for chickpeas and toss with the remaining 2 teaspoons olive oil. Add them to the baking sheet with the chickpeas.
Roast chickpeas and jalapeños for about 30 minutes, stirring halfway, until chickpeas are crunchy and jalapeños are softened and slightly charred. Let cool about 10 minutes.
Add the drained black beans, chopped cilantro, and sliced green onions to the bowl with the cooled quinoa. Add the roasted chickpeas (reserve jalapeños for the dressing).
Dice the roasted jalapeños and place them in a mini food processor. Add 3 1/2 tablespoons fresh lime juice, 1 1/2 teaspoons agave, 2 1/4 teaspoons nutritional yeast, and 1/2 teaspoon kosher salt. Process until smooth, scraping sides as needed, then stream in 3 tablespoons olive oil with the processor running until the dressing is thick and smooth.
Pour the dressing over the quinoa mixture and toss until evenly coated. Cover and refrigerate at least 1 hour or up to overnight to let flavors develop.
Stir in the cubed avocado, taste and adjust salt if needed, then serve.