Searing is critical for adding flavor and texture to sous vided foods. When searing you want to make sure it happens as quickly as possible to minimize further cooking. Most sears should only take 1 to 2 minutes per side.
The key to a good sear is to first completely dry off your food with paper towels or a kitchen cloth. Then heat some oil in a pan until it just barely starts to smoke. It’s best to use an oil with a high smoke point like canola, sunflower, safflower or peanut. Once the oil is heated you place the food in the pan. After 1 to 2 minutes flip the food, give it another minute or two, then pull it off. The shorter it is in the pan the better. For some foods like thin steaks or fish fillets I will only sear one side to minimize the overcooking.