Add 2 tablespoons of the oil to a medium saucepan and heat over medium high heat. Add the onion and cook, stirring occasionally, until softened, about 3 minutes.
Add the cumin, coriander, salt, and rice and stir together for about 30 seconds. Add the water, cover, and bring to a boil.
Reduce heat to simmer and cook until rice is tender and the water is absorbed, about 20-30 minutes. Stir in the black beans and most of the cilantro, reserving about a tablespoon for garnish. Remove from heat, cover, and set aside to stay warm.
Add the remaining oil to a medium skillet over medium high heat and then add the sausages and cook, uncovered, until browned, about 3 minutes per side.
Pour the black beans and rice into a casserole dish and top with the cooked sausage. Garnish with remaining cilantro and serve immediately.
