Steak & Purple-Potato Salad
1 teaspoon lime juice 1 teaspoon chili powder 1/2 teaspoon salt, divided 1 clove garlic, mashed into a paste 8 ounces sirloin steak, trimmed 3/4 pound small purple potatoes, (see Tip), scrubbed 2 tablespoons sherry vinegar 1 tablespoon extra-virgin olive oil 1/2 teaspoon ground cumin 1/4 teaspoon freshly ground pepper 4 large radishes, sliced 3 …