1 Trim The Excess Fat From The Pork Shoulder Roast. Put The Roast, The Salsa Verde, Onion, Chicken Stock, Cumin Seeds, Coriander Seeds, And Oregano In A Large, Thick-Bottomed Pot, And Heat On High Heat. Bring To A Boil, And Reduce Heat To A Low Simmer. Cover And Simmer Until Meat Pulls Away Easily With A Fork, About 3 Hours. 2 Preheat Oven To 400