If you can stomach cottage cheese, I really like a recipe I found on TikTok: cottage cheese, bagel chips, cucumber, tomato, green onion, medium boiled egg, smoked salmon, and everything but the bagel seasoning.
Very minimal prep: wash and chop vegetables, batch-cook and peel the eggs. I kept all the ingredients separate (except the vegetables) and assembled each morning.
Another option, which is a bit easier on the stomach and good for chilly weather, is breakfast soup. I make one with chicken broth, bok choy, ginger, garlic and medium-boiled eggs. I store the eggs separately. Each morning, I reheat a portion of broth and ladle it over th egg in my bowl.
Binging with Babish on Youtube has some straightforward, simple recipes for this scenario! Here’s the link.