Where Does Pizza Come From? When you bite into a slice, thank ancient Egyptians, brave Italians, and buffaloes

HUMANS have eaten wild mushrooms for thousands of years. But it was the French who first raised them as a crop in the West. Caves near Paris were planted with mushrooms in the 1600s. The caves' dark, damp conditions were perfect for the fungi. Today, European markets carry dozens of mushroom varieties, from elusive morels to plate-sized porcini and balloonlike puffballs. American markets generally sell but one fresh mushroom: the table mushroom - the one the French first grew.

SALT was no sweat for prehistoric communities by the sea. But this vital nutrient was precious inland. Salt caves in Salzburg, Austria (it means "salt city"), made it an ancient center for the salt trade. Later, salt helped build the Roman Empire. Latin tribesmen found efficient ways to mine salt, and quickly became rich merchants.

WOULD you ever eat a lily? That's what onions are - so is asparagus. Most researchers think onions came from India. Trade moved them about the ancient world: Egyptians loved them, so did Greeks. Onions even grew in Babylon's famous hanging gardens. A different species of wild onion sustained French explorer Pre Marquette. Near starvation on the shore of Lake Michigan in 1624, he and his band feasted on a plant the natives called chicago.

THE secret of cheesemaking has been discovered by nearly every culture that keeps dairy animals: cows, goats, sheep, water buffaloes.... Water buffaloes? Yes, mozzarella (MOT-zuh-rell-luh) was originally made from the milk of water buffaloes. It still is in the Latium and Campania regions of central and southern Italy, where it was first made. The buffaloes were draft animals that originally came from India. Today, most mozzarella is made from cow's milk. Real buffalo-milk mozzarella has a finer taste and is rarely used to make pizza or lasagna. Instead, it is enjoyed at the end of a meal, as dessert.

WHEAT was the first plant to be cultivated by humans. Grains of wild grass 10,000 years old have been found cached in Swiss caves. But until 4,000 years ago, the flat bread made from ground wheat and water had the texture of dog biscuits - hard and heavy. Ancient Egyptians allowed the dough to ferment before baking. Microscopic one-celled organisms present in the air - yeast - would settle on the dough and begin to multiply, turning carbohydrates in the wheat paste into alcohol and carbon-dioxide gas. The gas is what makes bread fluffy and soft.

FOR most of its existence, the tomato was ignored or feared. Spanish explorers brought tomato seeds back from Peru, where the plant grew wild. The "golden apple" - the fruits were small and yellow - came to the Spanish-controlled kingdom of Naples about 1525. Neapolitans embraced tomatoes in their cooking right away, but the rest of the world thought the fruit was poisonous until about 1750. In 1830, the first known pizzeria in the world opened in Naples. Pizza came to New York in 1905.

Pizza Facts:

* 4 billion fresh pizzas were sold in the United States last year.

* 1.1 billion frozen pizzas were sold in the US.

* 96 percent of Americans buy pizza out. Only 4 percent never go out for pizza.

* The average US family eats pizza at home 30 times a year.

* In 1994, total pizza sales in the US exceeded $20 billion.

* Pizza is the No. 2 entree sold in the US. It represents more than 10 percent of all food sales and is expected to surpass the No. 1-rated hamburger when sales are tallied for 1996.

* Pepperoni is the most popular pizza topping in the US.

* One of the top toppings in Europe? Tuna. (In Poland, cabbage and sausage is a favorite.)

* The biggest pizza ever baked, according to the 1996 Guinness Book of Records, was 122 feet, 8 inches in diameter. It was made in Norwood, South Africa, in 1990.

* Cookbooks specializing in Italian recipes make no mention of pizza prior to the 1950s.

* The first pizza delivery was in 1889, from the famous pizzeria Pietro il Pizzaiolo in Naples. The recipients: visiting King Umberto I of Italy and his Queen Margherita. The queen was eager to try this food she'd heard so much about but was reluctant to be seen in a pizzeria.