In a small skillet, heat 1/3 cup of the extra-virgin olive oil.
Add the shallots and cook over moderately high heat, stirring frequently, until golden brown and crisp, about 5 minutes.
Using a slotted spoon, transfer the fried shallots to paper towels to drain; reserve the shallot oil.
In a medium saucepan, cover the lentils with 2 3/4 cups of the chicken stock and bring to a boil over high heat.
Add the bay leaf and thyme, cover and simmer over low heat until the lentils are tender, about 30 minutes.
Drain the lentils and return them to the saucepan; discard the bay leaf. Stir in the parsley and the reserved shallot oil and season with salt and pepper. Cover and keep warm.
Meanwhile, in a large heavy skillet, heat 1 tablespoon of the olive oil until almost smoking.
Flatten each piece of pork tenderloin slightly with the palm of your hand and season on both sides with salt and pepper.
Working in batches, if necessary, add the flattened pork to the skillet and cook over moderately high heat until well browned and just cooked through, about 4 minutes per side. Transfer the pork to a plate and keep warm.
Add the wine to the skillet and bring to a boil. Cook, stirring, until reduced by half, about 2 minutes.
Add 1/2 cup of the chicken stock, the mustard and the remaining 2 tablespoons of olive oil. Boil, whisking constantly, for 1 minute. Remove from the heat.
Stir the remaining 1/4 cup of chicken stock into the lentils and bring to a simmer over moderately high heat.
Spread the lentils on a platter, arrange the pork on top and drizzle with the mustard sauce. Garnish with the crisp shallots and serve at once.