In a medium saucepan, bring the water to a boil. Add the quinoa, salt, and chipotle powder, and turn the heat to low. Cook, covered, for 15-20 minutes, or until all of the water has evaporated and the quinoa is tender. Remove from the heat and let sit for 5 minutes.
In a medium bowl, mix together the quinoa and egg. Press the mixture into the bottom and up the sides of a greased 9-inch pie plate. Bake for 20 minutes. Let cool while you prepare the filling.
In a medium skillet over medium heat, heat the olive oil until shimmering. Stir in the red onion and sauté until translucent, 3-5 minutes, stirring frequently. Add the bell pepper and smoked paprika to the pan. Saute for 3-4 minutes, or until the pepper is tender. Stir in the beans and season to taste with salt and black pepper.
In a large bowl, whisk together the eggs, milk, cheese, and bell pepper mixture. Pour into the quinoa crust. Place the uncooked quiche on a parchment-lined baking sheet (to catch any filling overflow or spills) and bake for 35-50 minutes, or until set. Let stand for at least 5 minutes before serving.
Both the quinoa and the crust can be prepared ahead of time! Just store, well wrapped, in the refrigerator until you are ready to make the filling.