I have SV London Broil Twice. Both instances the results were dry. Here is what I did, 2.5 pounds:
Poked 1/4 inch holes on both sides of meat
Dried meat and applied rub of salt, pepper, ground onion and garlic
cooked 12 hours/ 132 degrees
Finish in very hot cast-iron skillet with vegetable oil and butter. Quicky turned meat so butter side up and searzalled top with modest caramelization and turned and did same...old told about three minutes finishing
Result: Beautifully pink medium rare, perfectly tender...bag had about 1.5 cups of liquid...no juice in the meat. Any ideas?