Three Bean Minestrone Soup

Bahan-bahan (8 porsi)

• 1 tablespoon olive oil
• 1 large onion (chopped small, about 2 cups)
• 8 cups beef stock or 8 cups water plus 3 tablespoons beef base
• 15 ounce can tomato sauce
• 6 carrots (sliced 1/4" thick, about 3 cups worth)
• 4 stalks celery (trimmed and sliced 1/4" thick, about 2 cups worth)
• 14 ounce can kidney beans
• 14 ounce can navy beans or white beans
• 14 ounce can black beans
• 2 teaspoons dried oregano
• 1 teaspoon dried thyme
• 1 teaspoon kosher salt (adjust to taste (I added another 1/2 teaspoon, because my beef stock wasn't very salty at all))
• 1/2 teaspoon freshly ground black pepper
• 4 cups cooked pasta (I used a brown rice penne pasta)
• finely grated Parmesan or Pecorino Romano cheese
• Optional: 1 pound Italian or hot sausage