I rotate three, basic breakfast-types:
1) full-fat greek yogurt (I think it's 12% fat), topped with non-sugar, high protein (I think it's mainly pea-protein) "granola", and either some raisins on top, or a small, sour, diced apple mixed with the yogurt. If not apple-season, then occasionally a banana, but usually plain granola and yogurt+raisins.
2) Same full-fat greek yogurt mixed with small amounts of high-quality ketchup ("Mutti" is my main brand for any tomato-preserves, but tomato paste and a tiny bit of sugar and oil works too, if unavailable), sea-salt, and a robust amount of roughly-ground black pepper. I use this as a dipping sauce for 3-4 whole carrots, cut into practical strips, and if the celery looks nice, I do a 50-50 mix between carrots and celery "sticks".
3) Simple"frittata". Rough-chop an onion or two, peel and rough-chop 2-3 potatoes, fry them in a little bit of butter and some non-olive-oil on high temperature. Stir frequently.
After 5-8 minutes, I "chop" (or divide, really) a handful or two of whole, frozen broccoli-heads (each head is a "crown", the kind you can hold between your thumb and index finger). Add that to the pan, and continue to stir for about 3-5 minutes, until the broccoli-crowns are just right (I usually taste one to be sure, but you get a feel for it). Add sea-salt and black pepper as wanted.
Lower temperature to about half, and crack 4-5 eggs, depending on size, directly onto the vegetables. Scramble them quickly with the spatula to get an even spread, which also lowers the temperature of the pan. "Flip" (or really, awkwardly turn around) all the pieces of the frittata after about 2-3 minutes depending on your stove. Add a tiny bit of extra salt for the eggs.
Let the other side get a nice golden shine, and then serve.
These are pretty solid breakfast-concepts that keep me full for most of the day, and I end up (usually) only eating breakfast and supper.
The frittata is the best one, since it's both a warm dish and very filling, but can get very "samey" if eaten too frequently. Youghurt-ketchup dipping and raw root vegetables is incredibly effective for weight-loss, in the sense that, when I do it, I sometimes only eat it for the entire day.
But raw vegetables can also leave you feeling oddly.. I dunno cold, or sparse? When done for more than a few days I start longing for a hot breakfast. if nothing else it makes you think how quickly some foods are digested, and how much the feeling of satiety can dictate your food consumption.
The yogurt and bland, high-protein granola + raisin/fiber-fruit is the laziest option, and the least satisfying in general. But that's how lazy dishes work, I guess. It's "fine", in the sense that it is the least I can do.
All options served with 2-3-4-5 cups of black tea.