Heat some oil in a saucepan over low heat. Add the onion, the garlic and the cumin. Cook, stirring, for 3 minutes until soft. Stir in currants for 1 minutes. Stir in quinoa and water. Bring to a simmer. Simmer, stirring occasionally, for 14 minutes until liquid is absorbed and quinoa is tender. Cool.
Boil pumkin and potato in a saucepan of boiling salted water for 15-17 minutes until tender. Drain well. Return to pan. Cook, shaking pan, over low heat for 1 minute until excess water evaporates. Mash them. Transfer to a bowl. Cool for 10 minutes.
Place flour and breadcrumbs on separate plates. Place egg in a shallow bowl.
Combine quinoa mixture, pumpkin mixture, feta, coriander and extra flour in a bowl. Season well. Shape into twelve 10-12cm croquettes. Dip in flour, then egg, then breadcrumbs. Transfer to lined tray.
Add oil to a frying pan to come 2cm up side. Heat over medium-low heat. Cook croquettes, in 3 batches, turning, for 4 minutes until crisp. Drain on paper towel. Serve with relish, lemon wedges, coriander and salad.
