Heat 1 tablespoon of sesame oil in a large soup pot or dutch oven over medium-high heat. Once the oil is sizzling, add shrimp in a single layer; sprinkle the shrimp with dried basil, salt, and black pepper. Cook shrimp for about one minute on each side, or until firm and pink. Use a slotted spoon to transfer the cooked shrimp to a cutting board.
In the same soup pan add the remaining sesame oil. Bring oil to a low sizzle over medium heat.
Add in the sriracha sauce, yellow onion, and red bell pepper; sauté for 4 minutes, stirring occasionally, or until the onion and pepper have softened. Add in the ginger and garlic and cook for about 1 minute or until fragrant.
Add the chicken stock and water to the soup pot, stir well to combine. Turn the heat up to high and allow the soup to come to a rapid boil, this should take only a minute or so. Add in tomato paste, garlic powder, onion powder, celery salt, soy sauce, and rice vinegar; stir well to combine. Reduce heat to medium and simmer broth for 8 minutes.
While the soup is simmering, chop the cooked shrimp into bite sized pieces; set aside. Roughly chop the baby spinach; set aside.
Add the dry ramen noodles to the broth and cook for 2 minutes, stirring as needed. Stir in chopped shrimp, spinach, and lemon juice, mixing well to combine before removing the pan from heat. Taste the broth and adjust spices as needed. Ladle the soup into bowls and serve at once.
If you plan to make this ahead of time, I advise making the broth and noodles separately. Drain the noodles and pat them dry, then stir them in right before re-heating and serving. This will help avoid the noodles becoming soggy and soaking up all of the broth.