Shrimp Pho

Combine chicken stock, vegetable broth, shallots, soy sauce, fish sauce, ginger, rice vinegar, brown sugar, garlic, pepper, cinnamon stick, and star anise in a large pot. Cover and bring to a boil. Reduce heat to medium-low and simmer, covered, until flavors combine, 1 to 2 hours. Strain out solids and return broth to the pot. Bring a large pot of water to a boil. Add rice noodles and cook until opaque, 4 to 5 minutes. While noodles are cooking, saute shrimp with soy sauce and garlic in a skillet until shrimp are cooked through, 3 to 5 minutes. Drain noodles and rinse until cold water. Divide among 6 large soup bowls. Ladle hot broth over noodles and top with shrimp, bean sprouts, and green onions. Serve basil, cilantro, mint, and lime wedges alongside.