Step 1

Heat oil in large skillet on medium-low. Add onion and 1/2 teaspoon each salt and pepper and cook, covered, stirring occasionally, 6 minutes. Uncover and cook, stirring occasionally, until golden brown and very tender, 8 to 10 minutes more. Increase heat to medium. Add beef and cook, breaking up into very small pieces, until beginning to brown, 6 to 7 minutes. Add garlic and paprika and cook, stirring, 1 minute. Move beef to edges of pan, creating space in center. Add tomato paste and cook, stirring, until dark red, about 1 minute. Gradually stir chicken broth into tomato paste until fully incorporated, then stir in raisins. Mix in beef and simmer 1 minute. Remove from heat and toss with olives and brine; let cool completely.

Step 2

Meanwhile, heat oven to 425°F. Line baking sheet with parchment paper. Roll pie crust 1/8 inch thick, then cut out 4-inch rounds. Refrigerate dough as you work if necessary. Reroll and recut scraps to make 14 to 16 rounds total.

Step 3

Divide beef filling (heaping 1 tablespoon each) among rounds. Brush edges with water or egg if using, fold each round in half and press with fork to seal. Transfer empanadas to prepared baking sheet and brush with egg if using. Bake until golden brown, 16 to 20 minutes. Serve with sour cream if desired.