Heat the broth in a small pan. Heat 4 tbsp of the oil in a pan, add the shallot and the aromatic herbs, and then cook for a couple of minutes. Add the lentils and toss briefly, pour over the broth and cook for 18-20 minutes stirring from time to time and adding a few tbsp of hot water or broth if getting too dry.
When lentils are almost cooked, discard the herbs and season with salt and pepper. Cook the Pappardelle in hot salted water according to the package directions.
In the meantime, heat 4 tbsp of the oil in a large pan and sauté the shrimps for a couple of minutes. Drain the Pappardelle and transfer to the pan with the shrimps together with a few tbsp of the pasta cooking water. Add the lentils and toss to combine.
Divide the Pappardelle among the plates, drizzle with extra virgin olive oil, garnish with thyme and marjoram, and serve.