In a small food processor or powerful blender, combine the olives, almonds, lemon juice and tarragon. Pulse until roughly chopped. Add the oil in a steady stream and process just until the oil is absorbed.
The spread should have a coarse but easily spoonable texture. Let stand for about 30 minutes for the flavor to develop before serving.
Notes
For the olives, I like the canned green olives by the brands Lindsay or Early California.
To toast the almonds, spread on a baking sheet and bake at 350 degrees F., stirring once, until fragrant, 7 to 9 minutes.
Serving suggestions: with flatbread, or thin-sliced cucumbers or baguette.