Set a large soup pot on the stove over medium heat and add the olive oil.

Add the chopped onion to the pot. Cook for 2 minutes, stirring a few times, until it starts to soften.

Add the diced carrots and diced celery to the pot. Cook for 5 to 6 minutes, stirring often, until the vegetables look glossy and slightly tender.

Add the sliced garlic, dried oregano, 1 teaspoon kosher salt, and 1/2 teaspoon black pepper to the pot. Stir for 30 seconds, just until the garlic smells fragrant.

Pour the crushed tomatoes into the pot. Stir and cook for 2 minutes so the tomatoes darken slightly and lose their raw canned smell.

Pour the vegetable broth into the pot and raise the heat to high.

Bring the broth to a full boil.

Add the green beans and the drained cannellini beans to the boiling broth.

Lower the heat to medium so the soup bubbles gently. Cook for 5 minutes, until the green beans start to soften but still look bright.

Add the broken rice noodles to the pot. Use a spoon to press them under the broth so they start to soften evenly.

Cook the noodles for 4 to 6 minutes, stirring every minute so they do not clump together, until they are tender but not mushy.

Add the baby spinach to the pot. Stir for 1 to 2 minutes, until the spinach wilts into the broth.