Cut up the eggplant into cubes. Put the cubed eggplant in a colander and sprinkle with salt. Toss well and set aside to drain for 20 minutes. This is an important step to remove the bitterness from the eggplant.
Cook the Italian sausage in a large skillet, breaking it up into small pieces, until cooked through, about 10 minutes. Remove from the pan and set aside. You can leave the rendered fat from the sausage in the pan. If you prefer a vegan version, skip this entire step and move on.
While the sausage is cooking, chop up the onion, zucchini, tomatoes, garlic, and basil.
At this point the eggplant should be well drained. Rinse off eggplant to remove excess salt and pat dry with a clean towel.
Heat the olive oil over medium - high heat in the large skillet. Add the eggplant and cook, stirring occasionally, until lightly browned. Add in the onion and garlic. Cover and cook over medium heat, stirring occasionally, until the vegetables are soft, about 10 minutes. The eggplant will absorb a lot of the oil, so you may need to add more so that it doesn't stick to the pan while cooking.
Stir in the zucchini, tomatoes, basil, Herbs De Provence and tomato paste, cover, and cook until just tender, about 10 minutes.
Add the cooked Italian sausage and season to taste with salt and pepper, then serve.