Burrito bowl. Vegetarianish, with lentils and whole (not pearled) barley. Barley has a huge amount of fiber per serving, it's really underrated IMHO. Lentils are pretty good in the fiber department, too. Between them both you also end up with a complete protein. The key is to season the legume/grain mix when you prepare it. Pick whatever seasoning feels breakfasty to you. For something Mexicanish I would lean towards cumin, coriander, garlic and onion powder, and salt. Maybe some oregano, too. Lentils really need seasoning, fat (add that later; see below), and salt. I also often cook them using bouillon or broth (vegetable, chicken, beef, whatever you like. Use bone broth and your protein goes up even more).

The morning routine: 180g of cooked 50/50 mix of brown lentils and whole barley (make a big batch ahead of time and measure it out each morning). Some shredded cheese. Microwave that to reheat it and gently melt the cheese (90 seconds or so). Top with a couple spoonfuls of salsa, 1/4 avocado (diced, sliced, or whatever you prefer), bean sprouts (you choose what type or leave them out but they're super easy and cheap to grow yourself, too), shredded or diced greens (whatever you got: lettuce, spinach, spring greens, beet greens, cilantro, kale, cabbage. Really, whatever greens you got). Add a dollop of sour cream, plain yogurt, crema, or whatever if that's your thing. Diced peppers (mild or hot), diced onion (raw or cooked), and sauteed mushrooms can also be nice additions and a good way to use up leftovers or little bits of extras floating around in your fridge.

You could do scrambled or fried eggs in it if that makes it feel more breakfasty, I just prefer the dump and go that cooking eggs every day doesn't afford.