Put the olives, almonds, garlic, lemon juice, and capers in the bowl of a food processor. (I don’t use a mortar and pestle for this because I like the slightly chunky bits of almonds in the finished tapenade.)
Coarsely chop the basil leaves, add them to the processor, and pulse the machine a few times to start breaking them down.
Add the olive oil and a sprinkle of salt. Pulse the food processor until the mixture forms a coarse paste, one that still has a little texture provided by the not-entirely-broken-down almonds.
The tapenade will keep for up to 1 week in the refrigerator.