The blanks in the flat below can be filled in with two words which differ only by a single letter.

The _ _ _ _ _ _ _ is roasted, tomatoes
   sliced fine;
The salad is ready, in artful design.
Potatoes are baked and I've chosen a
   wine;
The gravy has _ _ _ _ _ _ _ ed - we're ready to
   dine!

Answers:

CHICKEN
THICKENed

Credit:
The Enigma 
NPL Magazine
February, 2020
A. CHEMEM