Preheat the oven to 180°C (160°C fan/350°F/Gas 4).
Mix the garlic with the olive oil and brush the surface of the bread with the mixture. Place on a baking sheet and toast in the oven for a few minutes until lightly golden and crisp.
Combine the lemon zest, mayonnaise and crab meat. Stir through the micro basil leaves and season well. Spoon the crab mixture over each slice of bread and serve immediately with rocket leaves and a squeeze or two of lemon juice.