Begin by heating the olive oil in a large pot over medium heat.
Once the oil is hot, add the finely chopped onion, diced carrots, and diced celery. Sauté these aromatic vegetables for approximately 5-7 minutes, or until they have softened and the onion becomes translucent.
Stir in the minced garlic and continue to sauté for an additional minute, being careful not to let it burn, until the garlic is fragrant and golden.
Gradually pour in the vegetable broth, and add the bay leaf and dried thyme, stirring to combine. Bring the mixture to a robust boil over high heat.
When the soup reaches a rolling boil, add in the pastina, then lower the heat to a gentle simmer. Cook according to the package directions, typically around 5-6 minutes, or until the pasta is al dente and tender.
As the pastina cooks, fold in the chopped fresh spinach and allow it to wilt for an additional 1-2 minutes.
Carefully remove the bay leaf from the soup, then taste and adjust the seasoning with salt and pepper according to your preference.
If you like, stir in the grated Parmesan cheese, letting it melt into the soup until well incorporated for a creamier texture.
Serve the soup piping hot, beautifully garnished with a sprinkle of chopped parsley and an extra sprinkle of Parmesan cheese on top, if desired.
Notes
Consider serving the soup in rustic bowls, alongside crusty bread for dipping.