Persian Spinach Spread

• 1 1/2 cups plain yogurt
• 1 pound spinach
• 2 tablespoons unsalted butter
• 1 large yellow onion, finely chopped
• 1 teaspoon sea salt, plus more to taste
• 2 tablespoons olive oil
• 1 clove garlic, minced
• 2 to 3 teaspoons lemon juice, plus more to taste
• 1 to 2 teaspoons chopped fresh oregano
• Freshly ground black pepper to taste

Line a sieve or a small colander with a triple layer of cheesecloth and put the yogurt in it. Let the yogurt drain over a measuring cup for an hour or so, until it is reduced by at least a third; discard the liquid. Wash the spinach and chop it coarsely; you should have 2 1/2 cups.

Meanwhile, melt the butter in a nonstick skillet and cook the chopped onions with a big pinch of salt over low heat, stirring often, for at least half an hour, until soft and golden brown. You cannot hurry this part, or you will not get the rich sweetness you need from the onions. When the onions are caramelized, remove from the pan and set aside.

Add 1 tablespoon olive oil to the pan and sauté the garlic in it for 1 to 2 minutes, until it sizzles. Add the spinach and half a teaspoon salt and sauté the spinach until all the excess water has cooked away. Scoop the spinach out onto a board and chop it quite finely, but do not put it in a food processor—you don’t want a purée.

Combine in a bowl and stir together the caramelized onion, spinach, 2 teaspoons lemon juice, 1 teaspoon oregano, the drained yogurt, the remaining tablespoon of olive oil, and black pepper to taste. Taste, and season with additional salt, pepper, lemon juice, and oregano as needed. Chill the spread for an hour or so, and serve with crackers or flatbread as an appetizer.