Coarsely chop 1 onion and slice 3 cloves of garlic.
In a large skillet over medium-high heat, add 3 tablespoons of extra-virgin olive oil. Once heated, add chopped onion and sliced garlic. Cook until soft and translucent, about 4 minutes.
Add 3 anchovies and ½ teaspoon of red pepper flakes. Cook just until anchovies dissolve, about 3 minutes. Lightly crush one 28-ounce can of whole peeled tomatoes and its juices with your hands as you add them to the skillet.
Add 2 teaspoons of red wine vinegar and ½ cup chicken broth and cook until the sauce is thickened, about 10 minutes.
Thoroughly wash 1 pound of peeled and deveined large shrimp under cool, running, drinkable water.
Nestle the shrimp into the sauce and sprinkle with 3 tablespoons of capers and ⅓ cup of chopped Kalamata olives. Bring the sauce back to a boil, reduce heat to medium-low, and simmer, covered, until the shrimp are cooked through, no more than 4 minutes.
Season to taste with flake salt if needed—the olives, capers, and anchovies are quite salty. Eat up, Mama!