1Peel and slice onion into 1/4 inch slices. Wash and dry squash, zucini, and egg plant into 1/4 inch slabs.( Leave Peels ON )Zest 1/2 of the lemon and juice 1/2 also. Wash and dry grape tomatoes.
2brush all veggies with olive oil and lightly salt and pepper. Starting with onion (you need to cook onion the longest,till it is carmalized slightly) put veggies on VERY HOT grill,brushed side down, single layered, and brush top side with olive oil and salt & pepper lightly. Grill 1 - 2 minutes each side. You do not want them limp.Reserve 2 tablespoons oil.
3After grilling, dice into 1/4 inch cubes. In large bowl combine veggies,lemon juice and zest,cilantro,roasted garlic,grape tomatoes,and remaining olive oil. Salt and pepper to taste. gentlely mix. Serve warm or chill in fridge.