- Heat oil in a medium saucepan over medium-high heat.
- Add diced onion and cook, stirring, until translucent, 4 to 5 minutes.
- Add minced garlic and cook, stirring constantly, for 30 seconds.
- Add ground ancho chili, cumin and oregano and cook, stirring, until fragrant, about 30 seconds more.
- Add rinsed black beans, water and tomato paste; stir to combine.
- Bring to a simmer, reduce heat to medium-low and cook, stirring occasionally, until the beans are heated through and the sauce is slightly thickened, 8 to 10 minutes.
- While serving sprinkle chopped parsley on top and serve warm.