The less water you use when cooking peas, the less vitamin C is lost. Steaming helps to conserve this vitamin.
When boiling frozen peas, add enough water to cover, bring to the boil and then cover and simmer for 3 minutes. To microwave 227 grams (8oz) of frozen peas add 15ml (1 tablespoon) of water, place in a non metallic container and cover. Cook on full power for 4 minutes (750W) or 4 1/2 minutes (650W)