Granny Smith apple will take quite awhile to get done so I would reeommcnd cooking them before hand. Wash, peel and slice thinly. Place in water with lemon juice or vinegar or lemonade drink mix. Heck, I've used lemon lime soda in a pinch. What you need is the acid to keep the apples from turning brown while you peel and slice the rest Then drain well, toss in a large bowl with sugar/brown sugar, a pinch of salt, your spices of choice and a few tablespoons of flour. Pop into a large saute pan with a bit of butter. This is a to taste thing, some people like them very sweet, some people like the bite of the Granny Smith apples so they don't put in as much sugar. Granny Smith's won't get real soft and turn to applesauce but they will get softer. You're looking for that fork tender thing .Taste and adjust seasonings and sugar to your liking.