Preheat oven to broil.

Place whole tomatoes and bell peppers in two separate baking dishes.

Broil for 30 minutes, turning occasionally, until skins begin to blacken.

Remove dishes from oven.

Cover bell peppers in their dish and allow to cool.

Remove skins, cores, and seeds from the cooled bell peppers.

Cut bell peppers into 1/2-inch pieces.

Remove skins from tomatoes.

Crush the peeled tomatoes with your hands.

Reserve all tomato and bell pepper juices.

Coat a large skillet with olive oil cooking spray.

Heat the skillet over medium-high heat.

Sauté the diced eggplant for 5 to 7 minutes, or until browned.

Add the crushed tomatoes and bell peppers, along with their reserved juices, to the skillet.

Stir in the harissa paste and ground cumin.

Simmer for 5 minutes, or until the sauce thickens.