Heat the olive oil in a large pot over medium heat. Add garlic and onion, and sauté for 2–3 minutes until fragrant and translucent.
Stir in the diced tomatoes and tomato paste. Let them bubble for a minute while you pretend you’re hosting a cooking show.
Pour in the broth and add the dry pasta. Gently push the pasta down to submerge it as best as possible.
Bring the whole thing to a boil, then reduce the heat and simmer uncovered for about 10–12 minutes. Stir now and then so it doesn’t glue itself to the pot.
When the pasta is just about done, stir in the chopped spinach. Cook for another 2–3 minutes until the spinach wilts into delicious green ribbons.
Season with salt, pepper, and a pinch of red pepper flakes if you're feeling bold. Serve warm with Parmesan on top—because cheese.