Heat a large soup pot over medium heat. Add olive oil, minced garlic, diced onion, sliced carrots, and celery. Sauté for about 5 minutes or until the onions are soft and fragrant.

Add tomato sauce, diced tomatoes (with their juices), vegetable broth, basil, and oregano. Stir to combine, and bring the mixture to a gentle simmer.

Once simmering, add the frozen chopped spinach directly to the pot. Stir until the spinach thaws and is fully heated through.

Taste the soup and adjust seasoning with salt if needed, depending on the sodium content of your canned goods and broth.

For serving, divide the diced Swiss cheese into individual bowls and ladle the hot soup over the cheese to allow it to melt. Enjoy with crusty bread or crackers for dipping!