Heat 1 tablespoon of the oil in a large skillet over medium-high heat, and, working in batches, brown the meat on all sides. Use a slotted spoon to transfer each batch of browned meat directly to the slow cooker, then continue browning. Wipe out the pot between batches if a lot of liquid has accumulated at the bottom, to ensure even browning. Wipe out the pot and add the remaining 1 tablespoon of oil. Sauté the onion, garlic, and ginger over medium-high heat for 5 minutes.
