Preheat oven to 400°.
Combine vermouth and saffron in a small bowl; set aside. Heat oil in a large nonstick skillet over medium heat. Add onion and garlic; sauté 5 minutes or until tender. Add rice and chorizo; cook 1 minute, stirring frequently. Stir in the vermouth mixture, salt, red pepper, and broth; bring to a boil. Reduce heat; simmer 8 minutes, stirring constantly. Stir in tomato, bell pepper, and peas. Remove from heat; nestle shrimp and mussels into rice mixture. Cover with lid or foil; bake at 400° for 35 minutes or until all liquid is absorbed.