How to Make It
In a medium bowl, toss the flour with the baking powder, sugar and salt. In a small bowl, whisk together the egg yolk, water, milk, yogurt and oil. Stir the liquid into the flour mixture with a wooden spoon. Transfer the dough to a lightly floured work surface and knead briefly until smooth. Divide the dough into 4 pieces and shape each piece into an oval disk. Wrap each dough disk in plastic wrap and refrigerate until chilled, about 4 hours or overnight.
In a small bowl, stir together 1 tablespoon of the crème fraîche, 1 tablespoon of the lime juice, 1 tablespoon of the chopped dill and the horseradish and mayonnaise. Fold in the pineapple. Refrigerate until chilled, about 2 hours.
Set a large pizza stone in the bottom third of the oven. Preheat the oven to 500° for at least 40 minutes. In a small bowl, combine the remaining 1/4 cup of crème fraîche with the remaining 1/2 tablespoon of chopped dill and 1/2 tablespoon of the lime juice.
On a lightly floured work surface, roll out each piece of dough to a 9-by-7-inch oval. Set the ovals on the pizza stone and bake for about 3 1/2 minutes, or just until golden and puffed.
Meanwhile, in a bowl, whisk the oil with the remaining 1 teaspoon of lime juice and season with salt and pepper. Add the greens and toss to coat.
Set a hot naan on each of 4 plates and top with the greens. Cover the naans with the pineapple, half of the dill cream and the shrimp. Spoon the remaining dill cream on top and serve at once.