Heat canola oil or clarified butter in a heavy three-quart saucepan, preferably nonstick.

Add cumin seeds, mustard seeds, and fennel seeds and cook until the seeds start to pop.

Stir in the turmeric, onion, and ginger and sauté over medium heat until the onion is soft.

Stir in the arborio rice and cook, stirring, for about three minutes.

Stir in the chopped plum tomatoes, then gradually add the hot fish stock or water, about half a cup at a time, stirring constantly and adding more liquid as the rice absorbs it.

Continue adding liquid and stirring for approximately 15 minutes until the rice is almost tender and most of the liquid has been absorbed.

Stir in the lemon juice and bay scallops.

Cover and cook for about two minutes, then uncover and stir for a few seconds longer, until the scallops are just cooked through.

Season the risotto with salt and pepper to taste.

Fold in the fresh coriander and serve immediately.