Begin the beans earlier in the day (or the day before!) by placing in a 4 quart pot with the onion, garlic, and oil. Cover with cold water by 2 inches. Bring to a rolling boil and let boil for 5 minutes. Then cover and reduced heat to maintain a very low simmer. When the beans are barely tender, add the salt and dried porcini mushrooms and let simmer until completely tender (how long this will take can vary wildly--I use
Rancho Gordo beans and can count on beans within 3 hours or so). Then turn off the heat and set aside or store in fridge until the next day.