Evenly cut eggplant in half lengthwise. Lay the eggplant halves cut side up on a work surface.
Crosshatch the eggplant in a diamond pattern by running a knife tip deeply and diagonally left to right down the eggplant about 4 times making sure not to cut through the skin. Repeat the pattern from right to left making a diamond pattern.
Press the eggplant open with your hand and sprinkle salt into the crevices. Let eggplant rest on work surface for 30 minutes.
Preheat oven to 400 degrees.
Pick the eggplant up and gently squeeze the water out of it. Wipe moisture off the surface with a paper towel.
Brush the surface with olive oil and sprinkle with garlic powder. Lay the herb sprigs on a baking sheet and place the eggplant halves on top of them, cut side down.
Roast 1 hour. The eggplant will collapse during roasting, remove from oven and let rest 20 minutes before serving.