Soak the bread in chicken stock until falling apart.
Put the almonds, salt and garlic in a high-powered blender (such as Vitamix) and pulse until the almonds are pulverized. Add the soaked bread and any stock that was not absorbed by the bread into the food processor, then add the grapes and cucumbers. Pulse until the mixture is a smooth purée.
Add 1 tablespoon of the vinegar and pulse a few seconds to combine. Taste and add the other tablespoon if it needs it – grapes can sometimes be acidic enough to leave out the final tablespoon of vinegar.
With the motor running, drizzle in the olive oil. Blend until silky smooth. Turn off the motor and taste the gazpacho. Add more salt if needed.
Chill before serving, garnish with diced cucumber and almonds.