Yesterday I was invited to a barbeque party organized by an ALT ( Assistant Language Teacher) working at my school. It was held near my house, and about 30 people joined it. Most of them were ALTs whose first language is English. There were also some Japanese, some of them were the ALTs' friends or their colleagues. It was a good opportunity for me to be able to see my old friends and to make friends with new people. They were so polite and gentle, so I had a very good time. The organizer had prepared for the foods so hard. I learned how to make good foods for barbecue from him. I learned in which order I should put ingredients through the stick. I also learned I should put the meats which take about same time to be done in the same stick, otherwise one meat is not done if the other is done. Because of the organizer's elaborate preparation, all the foods I had were so good. Although it was Potluck party, I enjoyed the foods he prepared for the party better than those which the other people brought. The party started at noon, and it was still going on when I said good-bye to the organizer around six in the evening.
The organizer had prepared for the food very thoughtfully. "hard" is not good here, as it implies difficulty. You could use: carefully, considerately, of thoroughly.
I learned how to make good food for a barbecue, from him.
I learned in which order I should put the ingredients on to the stick/skewer. You are doing shish kebob, right?
I also learned I should put the meat which takes about same time to be done, on the same skewer, otherwise one meat is done before the other. (is done).
Because of the organizer's thorough/elaborate preparation, all the food I had was so good. Elaborate has the connotation of "over the top", or "overly complicated".
Although it was a potluck party, I enjoyed the food he prepared for the party better than that which other people brought.
The party started at noon, and it was still going on when I said goodbye to the organizer around six in the evening.