Alice Waters' Ratatouille

Ingredients

• 1 medium or 2 small eggplant, cut into 1/2-inch dice
• 4 tablespoons olive oil, divided, plus more to taste
• 2 medium onions, cut into 1/2-inch dice
• 4 to 6 garlic cloves, chopped
• 1/2 bunch of basil, tied in a bouquet with kitchen twine + 6 basil leaves, chopped
• pinch of dried chile flakes
• 2 sweet peppers, cut into 1/2-inch dice
• 3 medium summer squash, cut into 1/2-inch dice
• 3 ripe medium tomatoes, cut into 1/2-inch dice
• salt to taste