Sort through the beans to remove any debris. Soak in water for at least 4 hours, ideally overnight. If you want to skip this step, add boiling water to the slow cooker when starting to cook the beans.
Add the onions and jalapenos to the skillet. Cook for 4-6 minutes until beginning to brown. Add the garlic and cook for 30-60 seconds until fragrant. Add a splash of beer to the skillet to scrape up any of the browned bits.