For this recipe, you’ll have the best results if you make the lentils from scratch. You want them to still have some firmness. Al dente is best! With canned lentils, there’s no guarantee that they won’t be overly soft. That being said, I have made this recipe several times using the vacuum packed steamed lentils from Trader Joe’s. (They're one of my favorite Trader Joe's vegan products.) When doing this, I have replaced all of the lentils (including the French lentils du Puy) with a package of pre-cooked lentils. That makes this recipe incredibly weeknight friendly. The whole thing is ready to go in about fifteen minutes. One thing to note is that the package of Trader Joe’s steamed lentils contains 2 ½ cups of cooked lentils, while the full recipe listed here requires 3 ½ cups of cooked lentils. So to easily follow the instructions, buy two packages. Or halve the recipe, and then use 1 ¾ cups of the pre-cooked lentils.