In a large pot, add chicken, onions, carrots, potatoes (and other vegetables, if using), chicken broth, cumin, oregano, bouillon cube, and black pepper. Cover and bring to a boil then reduce heat to low for 30-40 minutes.
Remove the chicken from the pot and shred with two forks. Place the shredded chicken back in the pot.
Add the fideo noodles (or angel hair pasta) into the pot. Cook for another 10 minutes on medium heat. The noodles tend to absorb a lot of water so if you see that the soup needs more liquid, add 1 cup of water at a time.
Serve the chicken soup with lime wedges, saltine crackers and/or tostones. Enjoy!