Add the tomatoes, onion, garlic, cumin, and 1 cup of the chicken broth to a large blender. Blend until completely smooth.
Strain the blended tomato sauce through a fine mesh strainer into a bowl to remove any solids. Set aside.
Heat the olive oil in a large pot or Dutch oven over medium-high heat. Stir in the fideo pasta and cook for 3 to 4 minutes, stirring occasionally, until the pasta begins to light brown and blister.
Pour in the blended tomato sauce and cook for 5 minutes, stirring occasionally.
Add in the remaining 5 cups of chicken broth, chicken bouillon (if using), and salt. Stir to combine and bring to a boil.
Reduce heat to low and cook for 10 more minutes or until the pasta is tender and cooked through.
Taste and adjust salt if necessary. Serve immediately.