Serve with bagel chips or thinly slices baguettes that you toast in the oven.
To make ahead, combine the ingredients for the base and store in the fridge until ready to use. Do the same with the topping (storing in a different container). They can remain in the fridge for several days. Before serving, spread the base on your plate/platter and make sure to use the slotted spoon to scoop the tomatoes on the top.