Cook pasta in salted water until just barely al dente, drain.
Meanwhile while water boils, cut your onion, add to large pan with oil, salt, pepper and the dried seasonings spices. Cook until onion is translucent, adding bit of water to prevent burning if needed.
Add wine, let reduce by half. In small bowl, add the flour and 3 tbsp of the veggie broth, whisk until smooth. Add this and rest of broth, and the mustard to the pan, stir well and let gently simmer (uncovered) until sauce thickens slightly, about 3 min.
Add red peppers and tomatoes, cook 3 min more.
Add spinach, and cooked pasta, stir, cover, let cook together for a couple min.
Garnish with chili flakes if desired.