The French cook their vegetables in very little water so they keep the nutrients in the vegetables rather than let them seep out into the water.
– Use the minimum amount of boiling water or stock so that you only half-cover the vegetables (they should not be immersed). It will depend on the size of your pan and the quantity you are cooking.
– Add salt to the water before you cook the vegetables, not when they are cooked. The exception is when you are cooking peas where you add the salt at the end so the pea skins don’t toughen.
– Add a handful of vegetables to the boiling liquid at a time so you don’t bring down the temperature of the water. It should come back to the boil before you add each handful.
– Put the lid on the pan so that you steam the vegetables, checking every few minutes that the water hasn’t boiled away and using a fork to test the doneness of the vegetables.