<<Disclaimer: Verify this information before applying it to your situation.>>

Baked potatoes are my favorite food.  Here's a list of things I put on
them...

fresh avocado (same consistency as butter...)
pureed or finely chopped celery (use a blender to puree celery or onion or
   whatever veg.)
chopped, fresh rosemary (or other herbs) with a little bit of Extra Virgin
Olive Oil
pureed or finely chopped cooked broccoli
pureed raw broccoli (tastes different from the above)
prepared mustard (be sure you're comfortable with the vinegar)
sauteed mushrooms (sometimes with onion and green pepper added)
black olives (there are all sorts of black olives, from kalamata and Greek
Olives to the run of the mill canned variety...)
Mayonnaise (a dairy-free mayonnaise substitute--be careful, as it's made with
   grain vinegar)
whatever curry or masala sauce I have available (homemade or store-bought)
green peas
combinations of the above

If you go to a good salad bar, the best one in town with the most selections,
look at the selections there, it will give you some ideas...

Depending on where one lives, there are probably cooking courses designed
especially for people of the same gender, age, and (in)competency level as
oneself...;-)

I highly recommend one of these for someone who can't cook, who has a food
allergy/sensitivity/ or celiac disease, as otherwise you can easily be at the
mercy of others--who may be too distracted by the requirements of commerce to
look after your best interests.

Hope this helps.

Sue

One thing I forgot to mention:  if you have food allergies/sensitivities, be
careful of eating the same food all day, everyday, as that practice can lead
to "new" allergies to that food.  It's a good idea to rotate your foods, that
is, eat it no more than every three to five days...