What concepts are described in the following sentence?

"David Cameron is a leader in the United Kingdom where the dish Bacon sandwich, a variation of BLT, is from. Lettuce is one of the ingredients of the BLT sandwich which is a variation of a club sandwich."

Return the answer as pairs of triples.
Bacon sandwich DISH_VARIATION BLT
BLT INGREDIENT Lettuce
United Kingdom LEADER_NAME David Cameron
BLT DISH_VARIATION Club sandwich
Bacon sandwich COUNTRY United Kingdom