For Veal Meatballs: Sauté onions in vegetable oil, 2 to 3 minutes, or until soft. Add 2 tsp chopped garlic, thyme and pepper; continue cooking 1 minute. Let cool. Mix ground veal with onion mixture, mint, parsley and salt forming 48 small meatballs. Refrigerate until ready to use.
Boil tomatillos, until soft, about 15 minutes; strain and discard liquid. Toast 6 chiles in skillet until fragrant. Soak in water 30 minutes. Strain and rinse with more water. Combine tomatillos, chiles and 2 garlic cloves in blender; blend until smooth.
Sauté onions in 6 tablespoons oil, 5 minutes, or until soft. Add tomatillo mixture to pan; simmer an additional 5 minutes.
Peel shrimp reserving shells. Boil shrimp shells in 4 quarts water for 10 minutes. Strain and reserve broth.
Toast tortillas over open flame until they begin to harden and dark brown spots start appearing.
Add tomatillo mixture to shrimp broth. Stir in Epazote leaves and toasted tortillas. Boil for 15 minutes; season with salt. Pour mixture back into blender; blend mixture until smooth.
Cut remaining 2 chiles into thin strips and fry in remaining 2 tablespoons oil 10 seconds. Reserve.
Add shrimp and veal meatballs to soup. Bring to a boil and simmer 2 to 3 minutes or until veal and shrimp are cooked through.
Ladle 1-1/4 cups soup into bowl. Sir in a few drops of lime juice and some of the reserved fried chile strips. Garnish with onions, sliced lime wedges, fried tortilla strips and mint leaves as desired.