Add the onion, bay and lentils to a medium pot and cover with water. Bring to a boil over medium-low heat. Simmer the lentils 10 minutes, then add the potatoes and cook for 7 to 8 minutes more.
While the lentils and potatoes cook, heat a tablespoon of oil in a medium skillet over low heat and saute the shallots, garlic and peppers for a couple of minutes. Add the peas and heat through for 1 minute more. Transfer to a shallow serving bowl to cool.
In a food processor, add the stock, mint and cilantro. Process until it becomes a paste. Add to the bowl with the pepper mixture.
Drain the lentils and the potatoes and discard the onions and the bay leaf. Return the lentil mixture to the hot pot to dry for a minute, then add to the bowl with herb paste and vegetables. Add 3 tablespoons extra-virgin olive oil to the salad bowl and toss. Season with cumin, and salt and pepper, to taste. Toss again and serve.