1. Toast the rye bread in butter in a pan until it has taken a bit of color. Place on absorbent paper and sprinkle with salt.
2. Halve the avocado, remove the stone and cut into thin slices. Place approximately one quarter on each piece of bread. Drizzle with olive oil.
3. Top each piece with a thin slice of Castello Creamy White. Sprinkle with chives, oregano, salt and pepper.