To help with the hunger feeling, if you wait an hour after bf to give the solids, it will increase the hunger a bit. As PP said, BM is still the main source of calories at this stage, so you want to ensure your lo is getting all the BM and not filling up on solids.
As far as quantity, again, foods are experimental at this stage and you want to ensure that he is not taking too much so he is hungry for the next BF. The quantity your doctor suggested is just a guideline.... use your instinct and let your baby tell you when he is full. As soon as he turns away, stop the feed.
You can give 2 feeds at a sitting. I used to mix new foods into the cereals (as neither of my kids liked really liquidy solids). Just be sure to allow 3-4 days between introducing new foods to watch for allergies.