Place bok choy, onion, garlic, soy sauce, basil and ricotta cheese in a bowl. Mix until well combined.

Lay one sheet filo pastry on the bench and fold lengthways into thirds. Spoon some of the mixture onto the top of the pastry strip. Fold pastry over to form a triangle and continue folding the pastry strip.

Place triangle on a lightly greased tray. Continue to create filo triangles with the ricotta mixture, using a new sheet of filo each time.

Lightly spray triangles with olive oil before baking in a moderate oven, 180°C, for 10 minutes, or until golden brown.