Heat oil in a large Dutch oven over medium. Add chorizo; cook, stirring occasionally, until lightly browned, 3 to 5 minutes. Transfer chorizo to a paper towel–lined plate using a slotted spoon, reserving drippings in Dutch oven. Set chorizo aside.
Add onion to Dutch oven; cook over medium, stirring occasionally, until softened and beginning to brown, about 5 minutes. Stir in garlic, pimentón, and salt; cook, stirring constantly, until fragrant, about 1 minute.
Add chicken broth, lentils, potato, carrots, and reserved chorizo; bring to a boil over medium-high. Reduce heat to medium-low; simmer, uncovered, stirring occasionally, until lentils and vegetables are tender, 20 to 25 minutes. Season with additional salt to taste.
