Preheat the oven to 400°F.
Using a large round cutter, cut 9 circles from each puff pastry sheet. Use a smaller cutter to cut a hole in the center of 9 of the circles, making rings. Brush egg on the underside of each ring and press it onto a whole circle. Brush the tops with egg wash and place them on a baking tray.
Bake for 15 to 18 minutes, until puffed and golden. As they bake, the rings rise up to form baskets.
While the baskets bake, sauté the chopped onion in olive oil over medium heat for about 5 minutes, stirring often so it does not burn.
Once the onion is translucent, add the mustard seeds, ginger, garlic, and potato cubes and turn the heat down to low.
Cover and cook for about 10 minutes, until the potato cubes are tender.
Uncover, add the peas, turmeric, smoked paprika, coriander, salt, and pepper, and sauté for a couple more minutes.
When the baskets come out of the oven, gently press each puffed center down with a spoon, leaving the sides standing.
Spoon the spiced potato filling into the baskets, garnish with parsley if you like, and serve warm.