Place the chicken thighs in a bowl. Drizzle with olive oil, add salt, paprika, garlic powder, and black pepper. Mix until evenly coated.
Heat a large pot over medium heat. Add the chicken and sear for a few minutes on each side until golden. Scatter the sliced onion on top and let it soften in the juices.
Once the chicken is nicely browned, sprinkle the fideo pasta directly over the chicken. Pour in the broth and bring to a boil.
Cover, reduce to a simmer, and cook for about 10 minutes until the pasta is tender and the chicken is cooked through.
While it simmers, chop the lettuce and cucumbers, add the corn, drizzle with olive oil and lemon juice, season with salt and pepper, and toss.
Serve the one pot chicken and pasta with the fresh salad on the side.
