Oats porridge made with water and with a bit of milk, just a tad of sugar for taste, potentially a few slices of apple with that
Polenta, cooked with more water than usual
Semolina, cooked with water and milk, just a tad of sugar
Lightly cooked chicken breast with rice, maybe some green beans or cucumber with that (both as salads, the green beans from a can - the thin variety)
Potatoe mash, potentially with a bit of chicken, although it really needs to be the right sort of potatoes, so that's a bit risky
Neutral wavers (the stuff they hand out at holy mass)
Potentially neutral liquid supplemental nutrition
Dark bread with just a bit of butter and honey (although it depends on the variety of bread)