Grilled Cod With Spinach And Tomatoes

Ingredients

• 1 (4 ounce) fillet cod
• salt and ground black pepper to taste
• 1 pinch garlic powder, or to taste
• 1/4 cup roughly chopped spinach, or to taste
• 1/4 tomato, seeded and diced
• 1 tablespoon chopped onion
• 1 tablespoon olive oil, or to taste
• 1 tablespoon balsamic vinegar, or to taste
• 1 slice mozzarella cheese, cut into cubes