In a large pot, stir together the oil, onion, and garlic to combine. Sauté over medium heat for 5 to 6 minutes, until the onion is softened.
Meanwhile, dice the carrot and celery into ¼- to ½-inch (5 mm to 1 cm) pieces. This will help them cook faster. You should have 1½ cups carrot and 1⅓ cups celery. Add the carrot and celery to the pot and stir to combine. Sauté for a couple of minutes.
Stir in the ginger and sauté for 1 minute.
Add the thyme, sage, tomato paste, and broth. Increase the heat to high and bring to a boil, then reduce the heat to medium-high, cover, and simmer for 5 minutes, or until al dente (still a bit firm).
Add the pasta and cook, uncovered, stirring occasionally, until al dente, following the timing guidelines on the pasta package. Check on the pasta frequently while it’s cooking, as you don’t want to overcook it.
Once the pasta is al dente, remove the pot from the heat and stir in the parsley, lemon juice, cayenne pepper (if using), and salt and black pepper to taste. Serve immediately.