Combine sourdough bread and enough water to just cover in a bowl and stand until just softened (30 seconds), drain and squeeze out excess water. Transfer to a food processor with tarama paste, lemon juice and onion and process until smooth (1-2 minutes). With motor running, add 1 tbsp water, then gradually add oil in a thin steady stream, processing until emulsified (2-3 minutes). Season to taste and refrigerate until required. Taramasalata will keep refrigerated for 2 days.
Preheat a grill to high. Place baguette slices on an oven tray, drizzle each side with olive oil and season to taste. Grill, turning once, until golden and toasted (2-3 minutes). Serve with taramasalata topped with salmon roe.
Note Tarama paste, a concentrate made from cod roe, is available from Greek delicatessens and select fishmongers.
This recipe is from the May 2012 issue of Australian Gourmet Traveller.
"You can do just about anything with taramasalata - stir it through a risotto at the end, pair it with scallops, serve it as a dipping sauce for raw vegetables or fried school prawns. It's a mayonnaise using fish eggs in place of hen's eggs, basically, so just use it like a mayonnaise or an aïoli. You could even spread it on a sandwich."