Preparation Bring vinegars, onion, garlic, sugar, cayenne, bay leaf, and 1 1/2 teaspoons salt to a simmer in a small saucepan, then remove from heat and let steep 15 minutes. Discard bay leaf. Meanwhile, cook collard greens in a large pot of well-salted boiling water until just tender, 6 to 8 minutes. Drain well in a colander, pressing to squeeze out excess water. Transfer greens to a large bowl, then add pineapple and vinegar mixture and toss to coat. Cool to room temperature, tossing occasionally, about 1 hour. Cooks' note:Pickled collard greens can be made 4 days ahead and chilled. Serve cold or at room temperature.
Preparation Bring vinegars, onion, garlic, sugar, cayenne, bay leaf, and 1 1/2 teaspoons salt to a simmer in a small saucepan, then remove from heat and let steep 15 minutes. Discard bay leaf. Meanwhile, cook collard greens in a large pot of well-salted boiling water until just tender, 6 to 8 minutes. Drain well in a colander, pressing to squeeze out excess water. Transfer greens to a large bowl, then add pineapple and vinegar mixture and toss to coat. Cool to room temperature, tossing occasionally, about 1 hour. Cooks' note:Pickled collard greens can be made 4 days ahead and chilled. Serve cold or at room temperature.