Cook, stirring frequently and using the end of your spatula to break up the tomatoes, until the tomatoes have burst, and the released liquid has reduced slightly. Add the tomato paste and cook for 1-2 minutes more.
Add broth and lemon juice and bring to a simmer, scrape up any stuck on bits from the bottom of the skillet, and bring to a simmer. Add the shrimp and stir to coat.