Each pouch contains a pre-measured portion of the dry mix, so you do not need to weigh or scoop the buckwheat, seeds, or vegetables. To get a good result, follow the preparation instructions printed on the pouch itself: the brand specifies how much water to add and how long to let the bag stand. Those details are more reliable than a general rule, because cooking time can vary with microwave wattage, altitude, and personal texture preference.
For this type of cook-in-bag product, the grains absorb hot water directly in the pouch, which keeps them separate and makes serving easy. Open the pouch carefully after cooking—steam will escape and the contents will be very hot. Tip the cooked mix into a bowl, fluff it with a fork, and add olive oil, butter, or a protein dish if you like.
If you are new to it, cook one pouch on its own first to see how firm or soft you like it. Green buckwheat and seeds have a slightly al dente texture, which is normal. If the grains are too chewy, add a little more hot water and let the pouch stand a minute longer; if they are too soft, use slightly less water the next time. Store any unused dry pouches in a cool, dry place.