Get more recipes from Marcus Samuelsson's summer grilling menu
Use a sharp knife to slice the vanilla bean lengthwise, then use the back of the knife to gently scrape the seeds into the pot.
Reduce heat to a simmer and cook until fruit starts to release its liquid and break down, about 2 minutes. Remove from heat and let cool for 10 minutes.
Put rhubarb strawberry mix, ice cream and yogurt in a blender and blend until smooth.