Half (or quarter) the Green Olives, trying to separate out some/most of the garlic; set aside.
Zest the lemon; set aside.
Peel and finely chop the garlic; set aside.
Add the pasta to well-salted boiling water & cook until al dente. Don't drain.
While the pasta is cooking, place the cashew halves in a DRY heavy skillet over medium heat. Shake frequently until they begin to lightly brown. Careful! They burn quickly! Remove from the skillet and set aside.
Put the oil & butter in the skillet and fry the olives for 2-3 minutes until they begin to soften and blister.
Add the fresh chopped garlic, the garlic from the jar, chili flakes, pepper, and lemon zest. Fry for another minute - be careful that the garlic doesn't burn.
Turn heat to low.
Use a spider strainer to transfer the pasta straight from the pot into the pan.
Squeeze the lemon over the pasta then pour in about ½ cup of the pasta water.