Cut 3 eggplants in half lengthwise, and place the 6 halves cut-side up on a cutting board.

Using a paring knife, cut around the perimeters, leaving a 1/3-inch-wide border, being careful not to cut through skin.

Cutting down through flesh, cut lengthwise into 1/4-inch strips.

Using a small spoon, scoop out strips, keeping skin intact.

Cut strips into 1/4-inch dice.

Set both the diced eggplant and shells aside.

Cut remaining eggplant, skin on, into 1/4-inch dice, set aside.

Heat olive oil in a large skillet over medium heat.

Add onion, and cook, stirring occasionally, until soft and slightly browned, about 8 minutes.

Add diced eggplant, bell peppers, 1/2 teaspoon salt, and 1/4 teaspoon black pepper.

Cover and cook, stirring occasionally, until browned, 6 to 8 minutes. If mixture starts to become dry, add additional tablespoon olive oil.

Remove from heat and set aside.

Preheat the oven to 350°F.

Place couscous in a medium heat-proof bowl.

Pour 1 cup boiling water over couscous.

Cover with clean kitchen towel and let sit until slightly cooled, 10 to 15 minutes.

Fluff with a fork.

Add lemon zest, ricotta, parsley, remaining 1/2 teaspoon salt, and remaining 1/4 teaspoon pepper.

Add reserved eggplant mixture, roasted garlic, and cherry tomatoes. Stir to combine.

Fill each reserved eggplant shell with couscous mixture.

Cover with aluminum foil.

Bake until warm throughout and shell has softened, 20 to 25 minutes.

Remove foil, and continue cooking until tops are toasty brown, about 20 minutes. Remove from oven.

Sprinkle with remaining parsley and serve.