Combine the shrimp, 2 tablespoons of the oil, the red pepper flakes, and the salt in a large bowl. Stir to completely coat the shrimp.

Heat a large skillet over medium-high heat. Cook the shrimp in a single layer until the bottoms are browned, about 2 minutes. Flip the shrimp and cook another minute. Remove the shrimp to a clean bowl or plate.

In the same skillet, heat the remaining tablespoon of oil. Add the onion and cook, stirring often, until the onion is soft and starting to brown. Add the garlic and cook an additional 30 seconds.

Pour in the broth and scrape up any bits on the bottom of the pan. Let the broth cook for a minute or two, then stir in the tomato paste. 

Once the tomato paste is incorporated, add the fire-roasted tomatoes and oregano. Turn the heat down to medium and continue to cook until the sauce is thickened, 10-15 minutes. 

Taste, and add the sugar, if needed. Stir in most of the parsley, reserving a little for serving. Stir in the shrimp and any juices that have accumulated.

Taste and season with more salt and red pepper flakes, as needed. Serve over pasta, rice, vegetables, or even with crostini!