Lentils do not require any soaking or precooking, they can be cooked in boiling liquid and drained, or simmered until cooked and all liquid has been absorbed, or added into a soup and simmered in the cooking liquid. Split red lentils will cook in around 10-15 minutes, brown and green lentils take up to 40 minutes.

Larger beans do need to be soaked and then cooked. Most beans will almost treble in volume when cooked, the length of cooking time varies depending on type of bean; age and size of bean so cooking times are approximate. Because the beans need to simmer for a long time, it is worth doing extra and freezing the cooked beans in useful sized bags – I find freezing them by the cupful works well. I can easily add a cup of frozen beans to a simmering dish without significantly affecting the seasoning.

Overnight method

Place beans in a saucepan and cover with 4 cups of water per 1 cup of beans. Soak the beans overnight in cold water. The beans will have softened by morning but they still need to be cooked. Replace the soaking water with fresh water and simmer the beans for 1-3 hours, or until tender but not soggy.

Quick cook method

Place beans in a saucepan and cover with 4 cups of water per 1 cup of beans. Bring to the boil and cook for 2 minutes, then leave to stand for one hour. This softens the outer layer of the bean in the same way as cold overnight soaking, but the beans will now still need to be cooked.
To do this simmer the beans until till soft , the time will vary so allow 1- 3 hours.

Kidney Beans and other similar sized beans simmer for 2-3 hours.
Soy Beans 3-4 hours.
Chick Peas 1-2 hours (Yum, fresh hummus).

Since beans require long cooking which uses electricity, cook several cups at a time and freeze them. You can add a frozen chunk directly into boiling soups and stews.

Cooks tips:
Ensure all beans are thoroughly cooked before serving – Kidney beans in particular can cause tummy upsets if not properly cooked. During cooking, a 15 minute period of rapid boiling is recommended for kidney beans
Cooked beans should be tender but not mushy
A dash of oil in the water will help prevent foaming
Don’t salt the cooking water as that will make the beans tough not tender
A pressure cooker will substantially reduce cooking times – if you have one, use it.