How to Make It
Heat 2 tablespoons of the olive oil in a large saucepan. Add the onion, garlic, rosemary, sage and half of the pancetta and cook over low heat, stirring occasionally, until the onion has softened, about 5 minutes. Add the chickpeas and cook, stirring, for 2 minutes. Add the wine and simmer until almost evaporated, about 4 minutes. Add the fish stock and tomatoes, cover partially and simmer over low heat until the chickpeas are tender, about 2 hours.
Discard the rosemary and sage sprigs. Transfer 1 cup of the chickpeas with some of the liquid to a food processor and puree; stir the puree into the soup and season with salt and pepper.
Heat the remaining 1 teaspoon of olive oil in a large skillet. Add the remaining 1/4 cup of chopped pancetta and cook over low heat, stirring often, until all the fat is rendered, about 7 minutes. Remove the pancetta and save for another use. Season the monkfish medallions with salt and pepper and sprinkle with the thyme. Add half of the medallions to the skillet and cook over moderate heat until lightly browned, about 2 minutes per side. Transfer to a plate and repeat with the remaining monkfish. Ladle the soup into shallow bowls. Arrange 3 or 4 monkfish medallions in each bowl, drizzle with olive oil and serve.