In a large pot, combine 2 cups water, the potatoes, vinegar, and 2 tsp salt. Boil covered until potatoes are just starting to get tender, about 10 minutes
heat oven to 425. Line sheet pan with parchment paper
Drain potatoes. Toss with olive oil, 1/4 tsp salt, and oregano. Arrange on baking sheet, cut sides down, on baking sheet. Roast until deeply golden and crispy, 20 - 40 minutes.
toss hot potatoes with the garlic. Move to serving bowl. Top with feta and dill.