Pasta with Arugula and Tuna and Cannelini Beans

One of the easiest dishes to make in my little blue four-ingredient cookbook is linguine with arugula. Not much to do: just boil pasta, toss it up with some olive oil, arugula, and freshly grated parmesan.
A few nights ago, I decided to turn this simple dish into a well-rounded satisfying meal, with the addition of cannelini beans and canned tuna.

Ingredients:
12 ounces pasta (I used whole wheat penne because I had it in my pantry.)
1/2 cup extra virgin olive oil
5 ounces baby arugula
1 cup freshly grated parmesan cheese (not the powdery stuff in a canister)
1 15-ounce can cannelini beans, drained and rinsed thoroughly
1 or 2 5-ounce cans of tuna
(You could make this with just tuna or just the beans.)

Directions:
1. Cook the pasta according to the directions on the package, drain thoroughly.
2. Heat about 4TBSP of the olive oil in the pan, add the pasta and the arugula. Toss over medium heat for one or two minutes, until arugula is just wilted then remove from heat.
3. Stir in the olive oil, parmesan, and tuna and beans, along with salt and pepper to taste.