Overnight oats are great. I sometimes make them using coconut milk, the stuff with no additives. And any fruit (fresh, frozen or cooked) that I have to hand. I also add a selection of nuts, seeds, goji berries, cocoa nibs, dried fruit, dessicated coconut, granola (homemade) or muesli, cinnamon, etc.
We also like pancakes made with just mashed banana and egg.
And I also make breakfast burritos and freeze them, when I have time. I don't make my own wraps/tortillas, but you could easily do this if you have time. I fill mine with diced potato, chicken, guacamole, grated cheese and salsa. We take them out the night before and then throw them in the air fryer.
And if I'm feeling really motivated (which is not very often), I'll make waffles and then freeze them so that they can be toasted in the morning. We would normally eat these on a Sunday with fresh fruit, Greek yoghurt, and some maple syrup.
Tim Spector eats yoghurt mixed with kefir, nuts, seeds and berries for his breakfast. I'm not really a breakfast person, but this sounds like it would be quite tasty and not too heavy. Great for your gut bacteria.