"large handful" is correct and usable in written English.
It can be used to refer to the amount of something, such as ingredients or objects. For example, "I added a large handful of herbs to the dish."
Finally stir in a large handful of rocket.
When done, season to taste, and mix in a large handful of chopped mint.
In a large handful of states, Michael barely cracked the top 40.
When the oil is hot add a large handful of frozen peas, some cashew nuts.
Both were garnished with a large handful of salad that had no dressing.
Stir-fry a large handful of crickets in hot oil until they brown.
Put a large handful of ice into a cocktail shaker and add the lemon juice and the elderflower cordial.
Finishing nails, roofing nails and common nails: one large handful of each, with a variety of sizes and an equal mix of galvanized and non-galvanized finishes.
I also added a large handful of rice, hoping that it would thicken and mellow the broth, and eliminate the need for cream.
Witnesses claimed that Jones ran from the crash, but immediately came back to take "a large handful of cash" from the car before leaving again.
