Place the olives, parsley, garlic, parmesan and almonds into a food processor and blitz until quite fine.
With the processor on low, slowly drizzle in the olive oil until all combined.
Check the texture and blitz to the smoothness you desire.
Many olives are stored in a salty brine. If you are buying marinated olives that are ready to serve, the may add too much salt to the pesto. Taste the olives first, if they taste salty on their own, rinse them first to remove some salt. Remember, you can always add salt at the end but you can't take it away.
The finer you process the pesto, the easier it is to spread.