For the pesto, add the arugula, almonds, cheese, garlic and salt to the bowl of a food processor and process until everything is finely chopped. Stop and scrape down the sides of the bowl occasionally. With the motor running, drizzle in the olive oil and lemon juice, and process a couple minutes more, until well pureed but not completely smooth.
For the salad, add the warmed drained beans to a large bowl, and add about ⅓ cup of pesto. Toss the beans and pesto together gently with a spoon, so the beans are well coated in the sauce. Again, be gentle so as not to crush and puree the beans. Taste and adjust for salt, if needed. Set aside.
In another large bowl, toss the arugula or greens of your choice with the small amount of olive oil, lemon juice and the salt, until the greens are well dressed.
To serve, on each plate layer: some dressed greens as a base, then some beans, and finally some croutons. Add a grating of cheese on each plate, if desired.
I don’t recommend mixing all the beans into the arugula, only as much as you’ll eat in one sitting. Leftover pesto’d beans can be kept in the refrigerator for 2-3 more days, and only add greens right before you plan to serve them.
