2 700-gram bottles Trader Joe's dark Morello cherries in light syrup
1 cup sour cream or thick Greek yogurt
2 Tbsp flour
zest and juice of 1 lemon
1/2 cup sugar
Drain the cherries over a saucepan big enough to hold the juice from both bottles. Set half the cherries aside for another use. Put the remaining cherries in a large bowl.
Whisk the flour into the sour cream or yogurt. Add the sour cream mixture to the cherry juice in the saucepan and whisk to combine. Bring the juice mixture to a boil over medium heat, and let boil gently for a minute - this will take away the taste of the raw flour.
Remove the pan from the heat. Stir in the lemon zest, lemon juice and sugar, and whisk or stir until the sugar is dissolved. Pour the hot liquid over the cherries in the bowl.
Let the soup cool to room temperature, and then chill in the refrigerator at least two hours or up to two days.