Drain the salmon. Remove skin and bones, if desired and mash with a fork
Preheat the oven to 200°C / 400°F / Gas Mark 6. Grease a baking sheet with a little vegetable oil
Add the red onion, cucumber and a squeeze of lemon juice to the salmon. Season with salt and pepper and mix well
Use a rolling pin to press out the slices of bread, then spread each one with some of the salmon mixture. Roll up and use short bamboo skewers or cocktail sticks to secure them. Place them on the baking sheet and bake for 8 - 10 minutes until golden and crispy. Serve whilst hot