Bring a large saucepan of water to a boil; add cauliflower. Boil 6 minutes or until crisp-tender; drain.
Heat a large skillet over medium heat. Add olive oil; swirl to coat. Sauté onion 2 minutes or until lightly golden. Stir in ginger, cauliflower, garam masala, kosher salt, and coriander. Cook 2 minutes.