For the Praline Paste: Place the sugar in a saucepan and add the water and lemon juice to prevent crystallization. Bring the mixture to a boil over high heat.
Meanwhile, toast the nuts separately in a 200°C / 392°F oven.
Lightly grease a marble slab with canola oil.
Stir the nuts into the sugar when it reaches 180°C / 356°F. Make sure