If you do not have thick Greek-style yogurt, start with 2 cups of regular yogurt; put the yogurt in a cheesecloth-lined colander over a bowl and drain for two hours in the refrigerator.
The volume should have reduced to 1 cup, resulting in nice, thick yogurt.
Discard the liquid.
Combine 1/2 pint blueberries and 1/4 cup honey with the rum in a small saucepan and cook eight minutes over medium-low heat, to cook the berries.
Puree with the lime juice.
Strain to remove skin and seeds.
Mix the yogurt with 2 tablespoons honey and the lime zest.
Whip the cream until it holds stiff peaks.
Fold the cream into the yogurt.
Toss the berries with the sugar.
Mix the berries with the mint.
Put a spoonful of the yogurt cream in each of 4 bowls.
Drizzle with blueberry sauce, top with berries and sprinkle with pistachios.