Wash and prep all vegetables. Dice eggplant, zucchini, and bell pepper into 1.5-inch pieces. Chop onion and mince garlic.

In a small bowl, combine salt, pepper, and herbes de Provence. Set aside.

Layer chopped onion and minced garlic at the bottom of the crockpot.

Add vegetables in layers: eggplant, bell pepper, zucchini, and tomatoes.

Pour the tomato sauce over the vegetables, followed by olive oil and balsamic vinegar.

Sprinkle the seasoning mix over the top and gently stir to combine.

Press vegetables down to ensure they are submerged in the sauce.

Cover and cook on LOW for 4.5 to 5 hours or HIGH for 2 to 2.5 hours.

Once cooked, let steam escape for a few minutes and stir in torn basil leaves before serving.