Remove the ribs and seeds from the jalapeño pepper and mince it.
Use a strainer to drain the black beans over a glass measuring cup, reserving the can liquid. (No need to rinse.)
In a large skillet, heat the butter and olive oil over medium high heat. Once melted, add the onion, bell pepper, jalapeño pepper, and garlic. Cook for 10 minutes, stirring occasionally until the onions are translucent and lightly browned. Add the beans, cumin, oregano, and kosher salt and stir to combine. Add 1/2 cup of the liquid from the black beans. Simmer 15 minutes until beans are tender.