Heat your oven to 500°F.
Toss the potatoes, fennel, carrots, and zucchini in 1 tablespoon olive oil.
Spread the vegetables in a single layer on a baking sheet. Roast 15-20 minutes, turning once, until the vegetables begin to caramelize.
Heat the remaining oil in a large soup pot set over medium heat.
Add the garlic, onion, and celery. Cook 6-8 minutes, or until softened.
Stir in the spices. Add the roast vegetables, tomatoes, and broth.
Simmer 10 minutes, or until all the vegetables are cooked through.
Season to taste with salt and pepper.