To prepare the herb blend, combine the first 4 ingredients, and set aside.
To prepare paella, combine water, saffron, and broth in a large saucepan. Bring to a simmer (do not boil). Keep warm over low heat. Peel and devein shrimp, leaving tails intact; set aside.
Heat 1 tablespoon oil in a large paella pan or large skillet over medium-high heat. Add chicken; sauté 2 minutes on each side. Remove from pan. Add sausage and prosciutto; sauté 2 minutes. Remove from pan. Add shrimp, and sauté 2 minutes. Remove from pan. Reduce heat to medium-low. Add onion and bell pepper; sauté 15 minutes, stirring occasionally. Add tomatoes, paprika, and 3 garlic cloves; cook 5 minutes. Add rice; cook 1 minute, stirring constantly. Stir in herb blend, broth mixture, chicken, sausage mixture, and peas. Bring to a low boil; cook 10 minutes, stirring frequently. Add mussels to pan, nestling them into rice mixture. Cook 5 minutes or until shells open; discard any unopened shells. Arrange shrimp, heads down, in rice mixture, and cook 5 minutes or until shrimp are done. Sprinkle with 1/4 cup lemon juice. Remove from heat; cover with a towel, and let stand 10 minutes. Serve with lemon wedges, if desired.