Method:
Place rice in a strainer and rinse under cool water until water runs clear. Transfer to a medium pot. Cook rice over medium-low heat, stirring gently, until fragrant and toasted, 3 to 5 minutes. Add water and salt, cover and bring to a boil. Reduce heat to medium-low and simmer, covered, until water is absorbed, about 1 hour. Uncover pot, fluff rice and set aside.
Heat oil in a large skillet over medium-high heat. Add onions and cook until just soft, 1 to 2 minutes. Add peppers, garlic and chili powder and cook, stirring occasionally, until softened, 2 to 3 minutes. Add diced tomatoes with their liquid and bring to a boil. Reduce heat to medium-low and simmer for 15 minutes. Stir in beans, then simmer until flavors are melded, about 5 minutes more; season with salt and pepper.
Spoon beans over rice, garnish with cilantro and lime wedges and serve.