Grilled Eggplant and Zucchini

We had two eggplants in our farm box this week. I once had eggplant Parmesan at a restaurant that was divine. And I've had eggplant Parmesan from the freezer section of Trader Joe's that is OK. But I think I tried to make it once without success. So I didn't know what to do with these eggplants. But since we were grilling chicken that night, I decided to try grilling the eggplant. And a zucchini, since I never know what to do with that, either. The zucchini came out decent. But the eggplant was disappointing. Eggplant has a strange consistency that seems hard to overcome. And a slight bitterness that needs to be masked. But here's how I made it.

3 Tbsp olive oil
2 tsp minced garlic (I used jarred minced garlic)
salt
pepper

Mix ingredients together to make marinade.

I sliced a small zucchini in half and brushed each half with the marinade.

I sliced the eggplant into 1/3"-1/2" slices and brushed the cut side of each piece with marinade(i.e. not the skin side).

I cooked them on the rack in the back of the BBQ to start, so they were not directly over the heat. After about 7-8 min, I realized they were cooking too slowly and when I turned them over, I moved them over direct heat.

If anyone knows a good way to cook egglant, let me know. I'm not sure what to do with the other eggplant we received.