Keeping 3 oz of food warm over a 20-30 minute period

After a phone consult with the drs office today, they moved me to pureed food, way sooner than I'd anticipated so I had not gone grocery shopping.  I did however have the recommended refried beans and topped them with some shredded cheese.  I've very quickly discovered the pace that I can eat, so of course my food was cold 3 bites down.  I was thinking that one of those coffee cup warmers might be a suggestion to set my little bowl on, but surely I'm not the only one that has pondered this.  Any other suggestions?

Get a plate for keeping baby food warm.  You fill the chamber with ho****er and it keeps the food warm.  http://www.amazon.com/Lansinoh-mOmma-Mealtime-Plate-Green/dp /B006W79MAY/ref=sr_1_2?ie=UTF8&qid=1430193532&sr=8-2&keyword s=baby+food+warmer

I love my little soup crockpot. I put food in there cold and plug it in, warms up in abut 10-15 mts and keeps it warm. I take it to work and eat right out of it. The steel inner lining keeps food warm.

http://www.amazon.com/Crock-Pot-SCCPLC200-R-20-Ounce-Lunch-Warmer/dp/B006H5V8US/ref=sr_1_1?ie=UTF8&qid=1430225611&sr=8-1&keywords=soup+crockpot