If possible, do this step ahead. If not, start here and disregard the times mentioned in this step: Rinse peas and lentils well and leave in water (together in one bowl) to soak for 30 minutes up to 4 hours. Prepare barley similarly and soak separately for 30 minutes.

Place large (8L) pressure cooker or 5L pot on med-high heat. When pot is warm, add olive oil. Meanwhile coarsely chop onion and add to pot after olive oil. Saute for 5-8 minutes till clear. While onions cook, peel carrots and slice into 1/4 inch "pennies".

Chop garlic and add to onion. Saute till fragrant.

Drain peas and lentils and add to pot. Mix well and let cook together until very fragrant, about 3-5 minutes.

For pressure cooker: Add carrots to pot. Rinse barley, add to pot and cook together for 1-2 minutes. Add 3L water (or double the height of the peas). In any case do not exceed pot limit. Season, cover and cook at med-high heat for 40 minutes (after achieving pressure). Turn off heat, leave pot closed for another 30 minutes.

For regular pot: Add carrots to pot and cook for two minutes. Add water till three times the height of the peas, or about 1.5 inches from pot rim. Season, bring to a boil and cook for 3 hours. Rinse barley, add to pot and continue to cook another 35 mins - 1 hour.

Best enjoyed after resting overnight or at least 2 hours.