Grind the coriander, caraway, and cumin seeds in a spice grinder until they are powdery and fine. Whisk the ground spices, oil, paprika, and cayenne in a bowl, then reserve 3 tablespoons of this spiced oil for prepping the vegetables.

Heat the remaining spiced oil and the garlic in a small skillet over low heat until the garlic is fragrant and tiny bubbles begin to form around the edges, about 8 to 10 minutes. Transfer the warm oil to a large bowl and let it cool for 10 minutes before whisking in the parsley, cilantro, mint, lemon zest, and lemon juice. Season with salt.

Brush the interior of the bell peppers and the cut sides of the eggplant, zucchini, and tomatoes with the reserved oil mixture, then season generously with salt.

Prepare a grill for medium-high heat. Clean and oil the cooking grate, then place the peppers, eggplant, zucchini, tomatoes, and shallots cut-side down on the grill. Cook until the vegetables are tender and show distinct char marks, between 8 and 16 minutes, turning as needed for even cooking.

Transfer the eggplant, zucchini, tomatoes, and shallots to a tray as they finish. Place the charred bell peppers in a bowl and cover tightly with plastic wrap for 10 minutes—the steam will loosen the skins for easy peeling.

Peel the skins from the bell peppers, eggplant, tomatoes, and shallots once they are cool enough to handle. Chop all the grilled vegetables into half-inch pieces and toss them gently with the chermoula dressing. Season with salt and pepper to taste and serve while still warm.