Maple syrup
Maple syrup was a liquid condiment derived from the maple tree. Whilst in New Orleans in the early 21st century, the Eighth Doctor chose a restaurant that served deep fried rice cakes, to which he added maple syrup, and a side of grits. (PROSE: The City of the Dead)
Maple syrup was a common condiment for waffles and pancakes. The Sixth Doctor and Peri at least once began their day with waffles, maple syrup and eggs in the TARDIS. (PROSE: Synthespians™) The Seventh Doctor once surprised Vincent Wheaton by coming over to Wheaton's house before the human had a chance to clean up his breakfast plates. On them were the messy remains of pancakes smothered with maple syrup. (PROSE: Warlock) At another point, the Doctor and Ace enjoyed a breakfast with jazz great, Duke Ellington, who relished every drop of maple syrup on his pancakes. (PROSE: Atom Bomb Blues)
Maple syrup also came in a synthetic variety, not derived from tree. Kyra Skye held this version of the condiment in contempt. When she once served pancakes to Sam and Fitz, she made a point of telling them that it was "real maple syrup, not that imitation rubbish". (PROSE: Unnatural History)