Wow, this was a tricky theme. I was sure that I had plenty of stamps featuring food and drink to meet this week's Sunday Stamps theme, but it turns out I didn't so I have had to stretch the theme a little. The 2 stamps below show rice being harvested and a rice field being ploughed, so it is food but not yet in its meal-ready form.
Ploughing a rice field, 1 cent stamp, British Guiana
Rice harvesting, 3d stamp, Sierra Leone