Have you tried pouring the baby food from the jar into a bowl in front of him? Does he eat that? If so, try making what you want him to eat and put that into the jar. Then, pour that into the bowl...he'll never know the difference.
He's getting old enough that soon you can probably level with him and say, "oh it's time to say bye bye to the "Baby Food," you're a big boy now etc. But before that time, personally, I'd basically just give him what I want him to eat and if he doesn't like it then I'd say, matter of factly, okay then I guess you aren't hungry yet. Try again in 2 hours. Still not hungry? Try again in 2 hours. Eventually, he's going to be hungry enough that he's going to eat what you give him. You aren't starving him or abusing him by making him go without food for a half a day.
You should nip it in the bud though! Don't want to encourage picky eater syndrome! My daughter is 3 now and eats whatever I cook, including garlic, onions, cilantro, even some spicy food. My rule at the table is, "If you aren't eating at the table, you're leaving the table." Period! She's learned that what's on the table is what is for dinner and if she doesn't eat it, then she'll be really hungry at breakfast. I don't accomodate for picky eaters (unless she's sick) and she's grown to love foods I've never seen a toddler even try!
Good luck!
(Note: I may be forgetting how old 8 months is! I like the suggestions by other moms to add rice cereal to smashed foods. Also, can he use his thumb and forefinger in a pincer motion? Like picking up small foods yet? If so, try the "big kid" baby foods with chuncks he can pick up - that's usually fun for them. Lastly, be watchful that the baby food you're using isn't loaded with sugar! He may not like the food you're cooking if it doesn't have the same sweet flavor!! (Sugar is BAD!)