This tasty riff on a falafel sandwich uses black beans and quinoa in place of chickpeas. Slideshow: More Recipes for Quinoa
In a small saucepan, combine the quinoa with the water and bring to a boil. Cover and simmer until the water is absorbed and the quinoa is tender, about 17 minutes.
Meanwhile, in a medium saucepan, heat the olive oil. Add the scallions, garlic, chile, cumin and coriander and cook over moderate heat until the scallions are softened, about 5 minutes. Add the beans and their liquid, season with salt and simmer over low heat until the beans are dry, about 3 minutes.
Stir the quinoa into the beans. Scrape half of the mixture into a food processor, add the flour and puree until smooth. Add the remaining bean mixture and the cilantro and pulse just to combine. Scrape the falafel mixture into a bowl and refrigerate until firm, about 15 minutes.
Preheat the oven to 425°. Line a baking sheet with parchment paper and brush with oil. Form the falafel mixture into 18 balls and press them into 1 1/2-inch patties. Transfer to the baking sheet and brush the patties generously with oil. Bake in the center of the oven for about 20 minutes until sizzling and crisp, flipping the patties halfway through.
In a blender or food processor, puree the tahini with the water, garlic and lemon juice and season with salt. Spread some of the sauce on the naan and top with chopped tomatoes, cilantro, cucumber, lettuce and the falafel. Serve right away.
The baked falafel can be refrigerated for up to 3 days and recrisped in a hot oven.