Drop some olive oil over the bread slices and roast them in a pan or in your oven (250°C).
Peel the cucumber and remove the seed. Cut the pulp into cubes and stir with 1 tbsp gin and buttermilk. Add salt and pepper to taste.
Cut the avocado into cubes and add some lime juice. Add salt, pepper and cayenne pepper as well, to taste.
Cut the spring onion into fine rings. Chop the cilantro. Cut salmon into cubes and mix everything together with the remaining gin (you can use more if you want), salt, pepper and lime juice. Keep in the fridge until the time you want to eat it.
Put some avocado and salmon on the roasted bread. Baste with cucumber and buttermilk and garnish with cress.