Cook pasta until al dente (tender to the bite). Scoop out 1/2 cup of cooking water and set aside. Then, drain pasta.

While pasta is cooking, finely chop 2 sage leaves and set aside. Cut remainder of sage into thin slices.

In a skillet, heat olive oil over medium heat. Saute garlic fro 20 seconds, then stir in sliced sage and beans and heat for 1 minute.

Remove from heat and add tomatoes and olives.

In a large bowl, toss together pasta, tuna, bean mixture, salt and pepper. If needed, add reserved cooking water to moisten and loosen pasta.

Sprinkle with chopped sage and serve warm.