Heat the olive oil in a skillet. Sauté the leeks until softened and translucent, about 5 minutes. Add the minced garlic and sauté until fragrant, about 30 seconds. Sprinkle in the salt, pepper, cumin, and turmeric. Stir into the oil to bloom the spices, about one minute. Remove from the heat and set aside to cool.
Pulse the parsley, cilantro, dill, lemon zest, and lemon juice in a large food processor or by hand until coarse, approximately ten pulses.
In a large bowl, whisk the eggs until smooth. Fold in the prepared herbs and leeks. Add the baking powder, whisking to incorporate.
Place an 8-inch heatproof skillet in the oven with the butter. Once melted, swirl the butter around the skillet to evenly coat. Add the egg mixture to the skillet.
Bake until the edges are set, and the middle just slightly moves, about 18-22 minutes.
Remove from the oven and cool in the skillet 10 minutes before serving.