Creamy Slow Cooker Tomato Soup

Bahan-bahan (6 porsi)

• 1 tbsp olive oil
• 1 cup finely diced celery
• 1 cup finely diced carrots
• 1 cup finely diced onions
• 28 oz can whole plum tomatoes (with juice)
• 1 tsp thyme
• 1/4 cup fresh basil
• 3 1/2 cups reduced sodium chicken broth (or vegetable for vegetarians)
• Parmesan or Romano cheese rind (optional)
• 1 bay leaf
• 2 tablespoons unsalted butter
• 2 tablespoons flour
• 1/3 cup grated Pecorino Romano cheese
• 1 3/4 cups reduced fat (2% milk, warmed)
• salt (to taste)
• black pepper (to taste)