Creamy Fish and Tomato Soup

Melt butter in a pot over medium heat; stir in onion. Cook and stir until the onion has softened and turned translucent, about 5 minutes. Stir in dill and cook until fragrant, about 1 minute. Add water, cream, and lemon juice; bring to a simmer. Add cod and cook until fish flakes easily with a fork, 5 to 10 minutes.

Stir in tomato soup until dissolved. Add shrimp and cook until bright pink on the outside and the meat is opaque, 2 to 5 minutes.