Creamy Broccoli Cheddar Soup

Name: Creamy Broccoli Cheddar Soup
Prep time: 10 min
Total time: 10 min
Cuisine: American
Ingredients: 3 tbsp. unsalted butter; 1 small white or yellow onion, diced; 2 cloves garlic, minced; 3 tbsp. all-purpose flour; 4 c. vegetable broth; 2 c. half-and-half; 2 small heads broccoli, cut into florets and stems cut into 1-in. pieces (8 to 10 c.); 3 oz. sharp white cheddar, grated (1 1/2 cups); kosher salt; Freshly ground black pepper; pinch of nutmeg; Greek yogurt or sour cream, for garnish (optional)