Heat oil in a large straight-sided skillet over medium-high. Add shallots and zucchini; season with salt and pepper. Cook, stirring occasionally, until tender and golden-brown in places, 5 to 7 minutes.
Add bulgur and ¼ teaspoon harissa; cook until nutty and fragrant, about 2 minutes. Add tomatoes, clam juice, and ½ cup water; bring to a simmer. Cover, reduce heat to low, and cook 10 minutes.
Meanwhile, season fish with salt, pepper, and remaining 1 teaspoon harissa. Nestle fish into bulgur mixture in a single layer, cover, and continue cooking until fish is just cooked through, 8 to 10 minutes (depending on thickness). Remove from heat, cover, and let stand a few minutes. Serve with mint and a drizzle of oil.
