
Heat 2 Tablespoons of butter in a medium-sized saucepan over medium-heat until melted.
Add onion, cook, stirring occasionally, until softened (about 5 minutes).
Add garlic and cook, stirring, until fragrant (about 30-60 seconds).
Add cumin, oregano, and salt and stir well.
Add beans and broth and stir until ingredients are well combined. Bring to a simmer over medium/low heat and simmer for 10 minutes, stirring occasionally.
Using a potato masher or fork, mash the refried beans until desired consistency is reached. If needed/if the beans seem dry, add additional broth, a splash at a time.
Add remaining Tablespoon of butter and the lime juice and stir well. Taste-test and add more salt or lime if needed.
Serve immediately, topped with cotija cheese or queso fresco, if desired.