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3 cups chopped leeks (white and light green part), rinsed and drained |
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1 medium size onion, sliced thinly |
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4 green onions in thin slices |
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2 medium size potatoes peeled and cut into ½ inch (1 cm) dice |
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¾ cups grated Gruyere cheese or similar |
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2 teaspoons balsamic vinegar |