Heat olive oil and butter over medium-high heat in a 6 quart Dutch oven or stockpot.
Add onions, carrots, celery, and parsley to the heated oil; cook for 5 minutes, or until just tender.
Stir in garlic and cook for 30 seconds more.
Add vegetable broth; stir in salt, pepper, dried oregano and bay leaf.
Bring to a boil; reduce heat to a simmer and cook for 5 minutes.
Stir in beans and corn kernels; continue to cook for 5 minutes. Taste for salt and pepper; adjust accordingly.
Add spinach and cook for 1 minute.
Remove from heat.
Ladle soup into bowls; sprinkle with parmesan cheese and serve with toasted bread slices.
Calories: 288 kcal | Carbohydrates: 43 g | Protein: 18 g | Fat: 7 g | Saturated Fat: 2 g | Cholesterol: 5 mg | Sodium: 548 mg | Potassium: 950 mg | Fiber: 12 g | Sugar: 3 g | Vitamin A: 2926 IU | Vitamin C: 11 mg | Calcium: 136 mg | Iron: 4 mg | Net Carbs: 31 g
Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.