Preheat the oven to 450.
First, season short ribs with salt, pepper, and 1 packet onion soup mix in a casserole dish. If have the time leave in fridge overnight to let seasonings soak in.
Next, place on top rack of oven 20 minutes to sear the short ribs. Then take short ribs out and lower oven heat to 325.
Now, place the onions, garlic and beef broth in with the short ribs. Sprinkle second packet of onion soup mix on the onions. Then cover tightly with tin foil
Next, place short ribs oven (on sheet pan in case spills) on the middle rack for 6 hours.
Finally, take out and serve on buttery mashed potatoes or rice. Happy Eating!