Preheat oven to 450°.
Place eggplant in a colander. Sprinkle with 1/2 teaspoon salt; toss. Let stand 20 minutes. Drain and pat dry with paper towels. Combine eggplant, bell peppers, onion, and 1 tablespoon oil in a large bowl; toss well. Spread eggplant mixture evenly in a jelly-roll pan coated with cooking spray; sprinkle with 1/4 teaspoon salt and black pepper.
Remove white, papery skin from garlic head (do not peel or separate the cloves). Cut off top 1/4 inch of garlic head using a serrated knife; discard top. Rub 1/4 teaspoon oil over bottom portion of garlic head. Add garlic head, cut side up, to eggplant mixture. Bake at 450° for 40 minutes or until vegetables are browned, stirring occasionally.
Heat 1 tablespoon oil in a large Dutch oven over medium-high heat. Add cumin, turmeric, ginger, and chicken broth. Bring to a boil. Stir in bulgur; cover, reduce heat, and simmer over medium-low heat 20 minutes or until liquid is absorbed.
Remove garlic from eggplant mixture. Separate cloves; squeeze to extract garlic pulp. Discard skins. Stir garlic pulp, eggplant mixture, parsley, and lemon juice into bulgur mixture.