Rinse split peas and lentils well and soak in water for 30 minutes to 4 hours.

Prepare barley similarly and soak separately for 30 minutes.

Place a large (8L) pressure cooker or 5L pot on med-high heat.

Add olive oil to the pot.

Coarsely chop the onion and add to the pot after the olive oil.

Sauté for 5-8 minutes until clear.

Peel carrots and slice into 1/4 inch 'pennies'.

Chop garlic and add to the onion.

Sauté until fragrant.

Drain peas and lentils and add to the pot.

Mix well and let cook together until fragrant, about 3-5 minutes.

For pressure cooker: Add carrots to the pot.

Rinse barley, add to pot and cook together for 1-2 minutes.

Add 3L water (or double the height of the peas). Do not exceed pot limit.

Season with salt and pepper, 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 until three times the height of the peas, or about 1.5 inches from pot rim.

Season with salt and pepper, bring to a boil and cook for 3 hours.

Rinse barley, add to pot and continue to cook another hour.

Let rest overnight or at least 2 hours before serving.