I suppose it varies by country/region. But it needs a traditional breakfast item of some type in it, or it's just a sandwich. In the US, we have some non-egg variations, such as fried chicken on a buttermilk biscuit, or a breakfast sausage (patty not link) and cheese biscuit. Then, of course, you could use waffles or pancakes as the "bread" and have them double as the breakfast components.