Generously salt a large pot of water.
Bring to a boil and add the pasta in. Cook until just over al dente, making sure not to overcook.
While the pasta is cooking, heat a skillet over medium heat. Add the butter or olive oil. Let the butter melt or the olive oil heat.
Add the shallots and sauté for about 2 minutes. Add the garlic and continue to sauté for another 2 minutes or until fragrant. Whisk in the flour until lightly browned, about 1 minute.
Slowly whisk in 1 cup of the milk and half of the lemon juice. Add the remaining 1 cup of milk and other half of the lemon juice whisking constantly. Stir in the lemon zest and the 3 ounces of feta cheese stirring constantly until the sauce bubbles and starts to thicken.
TIP: If you are using a lower fat milk, you might have to whisk in 1 or 2 more Tablespoons of milk to thicken the sauce. If you think the sauce is too thick, you can use the reserved pasta water to thin out the sauce.
Add the Italian seasoning and let simmer for about 2 minutes stirring occasionally.
When the pasta is done cooking, reserve about ½ cup of the cooking water and set aside. Drain the pasta.
Stir in the pasta, chickpeas, arugula with the sauce. Gently stir. Add in 2 to 3 tablespoons of reserved hot pasta water, which contains salt and starch for extra flavor and texture in the sauce.
Sprinkle the remaining 3 ounces of feta cheese on the pasta dish.
Serve warm with fresh parsley, crushed red pepper, pine nuts and extra lemon zest.