Combine 1-1/2 cups flour, undissolved yeast, sugar, salt and Italian seasoning in a large mixer bowl. Add water and oil beat for 2 minutes. Add enough remaining flour to make a soft dough. Turn out onto floured surface and knead** 5 to 6 minutes, until smooth. Cover dough and let rest 10 minutes. Combine butter and minced garlic, set aside.
Roll or press dough to fit into a greased 13×9-inch pan. Using a wooden spoon handle or a finger, poke holes in dough 1 to 2 inches over entire surface. Drizzle with garlic butter mixture. Cover and let rise 30 to 40 minutes, until doubled in size.
Bake in a preheated 375°F oven for 20 to 25 minutes, remove from oven.
While focaccia is baking make the vegetable topping. Put olive oil into a large skillet over medium heat, add onion and cook for 4 to 5 minutes, add zucchini cook for another 5 to 8 minutes stirring occasionally. Remove from the heat, stir in salt, Italian herb seasoning, pepper and tomatoes. Spread vegetable topping over partially baked focaccia.
Return to oven and bake an additional 10 minutes or until golden brown. Remove from oven and serve immediately.
*If you don’t have a thermometer; water should feel very warm to the touch.
**To knead the dough, add just enough flour to the dough and your hands to keep the dough from sticking. Flatten dough and fold it toward you. Using the heels of your hands, push the dough away with a rolling motion. Rotate dough a quarter turn and repeat the “fold, push and turn” steps. Keep kneading dough until it is smooth and elastic. Use a little flour if dough become too sticky, always working the flour into the ball of dough.