In a large skillet, heat 2 tablespoons oil over medium-high. Add zucchini in a single layer; sprinkle with cumin and coriander. Cook, turning once, until golden, about 8 minutes. Transfer to a plate. Season with salt and pepper; cover to keep warm. Reduce heat to medium and add remaining oil, onion, and garlic to skillet; cook, stirring, until softened, 5 minutes. Add tomato paste; cook 1 minute. Add beans and 1/2 cup water, season with salt and pepper, and simmer, smashing some beans with a spoon, until heated through.

With tongs, toast each tortilla over a burner until charred in places; wrap in a towel. Fill with sour cream, beans, zucchini, cheese, and radishes. Serve, with jalapenos, carrots, and lime alongside.