Drain sun-dried tomatoes from the jar and cut them into smaller pieces.
In a food processor, blend garlic, almonds and sun-dried tomatoes until chunky.
Add arugula and Parmesan cheese.
While blending, slowly drizzle the olive oil on top of the other ingredients until you reach the desired consistency. Be careful not to over-process the sauce as it might start to cook ruining the final product.
Finally, transfer the pesto in a bowl and incorporate the ricotta cheese, mixing well with a spoon. Salt, to taste