Preheat a skillet over medium-high heat. Add peppers and onions, and cook until soft, about 5 minutes. While the peppers and onions are cooking, scoop the eggplant out of the skin and mash it with a fork in a medium-size mixing bowl. Add the cloves from the roasted head of garlic and mash them in the bowl with the eggplant. Add the cooked peppers and onions to the bowl along with a generous amount of salt and pepper. Add a drizzle of EVOO and spread on the slices of ciabatta toast.
To roast the eggplant: Preheat oven to 400°F. Cut eggplant in half, drizzle with a little EVOO and a sprinkle of salt and pepper. Place eggplant halves on a baking sheet and transfer to the oven for about 45 minutes, until tender and golden brown. Remove from the oven and let cool.