"Borei Minei Meznonot" ("who creates forms of sustenance") is the bracha (blessing) made before foods that aren't "bread", but are still made primarily of wheat, barley, spelt, oats, or rye. Pasta and cheerios, for instance, are "mezonot", not "hamotzee" (bread). Afterwards, instead of full bentching, there's a much shorter blessing, Al HaMichya (it's about one paragraph long).
There are some foods that blur the line between the categories of bread and non-bread. No matter how much pasta you eat, it's always "mezonot." Certain breadlike products, however, (let's say a cinnamon bun) are more complicated, and may depend on how much you're eating and whether it's a meal or a snack. This is the logic behind the common practice that one slice of pizza is "mezonot", but two or more is "hamotzee" and needs bentching afterwards.
Many breadlike products can be made with apple juice instead of water, and according to many rabbis this means they're no longer "bread" and instead the bracha is mezonot. So you can buy a package of "mezonot rolls", as you'd probably seen here.
Some rabbis feel that the apple-juice trick doesn't work, it's still bread and therefore hamotzee. I believe the London Beth Din is more open to the idea of mezonot bread, and America's Orthodox Union less so; so ask your rabbi.