Briny capers and anchovies and salty feta offset the sweetness of the orange juice and dried currants perfectly in this Mediterranean-inspired pasta dish.
Bring a large pot of salted water to a boil. Add pasta; cook 2 to 3 minutes less than according to package directions. Reserve 1 cup liquid, then drain.
Meanwhile, in a large, straight- sided skillet, heat oil over medium-high. Add capers; cook until crisp, 1 to 3 minutes. Using a slotted spoon, transfer to paper towels.
Add garlic, anchovies, and zest to skillet; cook until garlic is fragrant, about 30 seconds. Stir in chard stems and currants; cook 2 minutes. Add orange juice; cook until evaporated, 30 seconds. Stir in chard leaves, season lightly with salt and pepper, and cook until stems are tender and leaves are just wilted, about 3 minutes. Transfer mixture to a bowl.
Combine reserved pasta water, 1/2 cup feta, and pasta in skillet. Cook, stirring, until pasta is cooked through and feta has melted into liquid, about 3 minutes. Add chard mixture; toss to combine. Fold in another 1/2 cup feta. Serve, sprinkled with capers, pine nuts, and remaining 1/2 cup feta.