In a large bowl, mix the flour and salt. Make a well in the center and add the egg. Gradually add the warm water, mixing until a dough forms.
Knead the dough on a floured surface for about 5-7 minutes until smooth and elastic. Cover with a damp cloth and let it rest for 30 minutes.
Roll out the dough into a thin sheet. Cut into thin strips to form the noodles. Cook the noodles in boiling salted water for about 3-4 minutes, or until they float and are tender. Drain and set aside.
Heat vegetable oil in a large pot over medium heat. Add the beef or lamb pieces and cook until browned on all sides.
Add the chopped onion and minced garlic to the pot. Cook until the onions are translucent.
Stir in the red and green bell peppers, tomatoes, carrots, and potatoes. Cook for a few minutes until the vegetables start to soften.
Add soy sauce, ground cumin, paprika, black pepper, and salt. Stir to combine.
Pour in the beef or vegetable broth and bring to a boil. Reduce the heat and let it simmer for about 20-25 minutes, or until the meat and vegetables are tender.
Divide the cooked noodles among bowls. Ladle the hot soup and meat mixture over the noodles.
Garnish with fresh cilantro or parsley and red chili flakes if desired.
Enjoy your meal!