Sauté Vegetables: In a large pot, heat olive oil over medium heat. Add the chopped onion, garlic, mushrooms, carrots, and celery. Sauté for about 5 minutes, until the vegetables begin to soften. Stir in the diced potatoes, and cook for another 3 minutes.
Add Tomatoes & Seasonings: Pour in the canned diced tomatoes, thyme, oregano, bay leaf, salt, and pepper. Stir to combine.
Add Broth: Pour in the vegetable broth, and bring the soup to a boil.
Simmer: Reduce the heat to low, cover the pot, and let it simmer for about 15-20 minutes, or until the vegetables are tender.
Add Beans & Peas: Stir in the cooked beans and green peas. Continue to simmer for another 5-7 minutes, until everything is heated through. Remove the bay leaf, and taste to adjust seasoning.
Serve with crusty bread or a side salad for a complete meal.