In a medium bowl, mix the spices until well combined then add the shrimp and one tablespoon of olive oil. Toss until well-coated.
Heat a large Dutch oven over medium heat with two tablespoons of olive oil. Cook the seasoned shrimp for 1-2 minutes on each side until just cooked through. Remove the shrimp from the pan and set aside on a covered plate.
Add onion, celery, bell pepper, half of the green onions, and minced garlic. Cook for 4-5 minutes then stir in the tomato paste and season with smoked paprika, a good pinch of kosher salt, and freshly ground black pepper.
Melt butter into the vegetable mixture and sprinkle the flour over the top. Cook for 3-4 minutes, while constantly stirring, until the flour has slightly darkened. It will look clumpy.
Slowly stir in the broth until no lumps of flour remain. Scrape off the fond (the flavorful bits stuck to the bottom of the pot). Add the corn kernels and cashew cream. Bring to a boil then reduce to a simmer over medium heat. Cook for 5-7 minutes, stirring occasionally.
Season to taste with more kosher salt, a generous amount of freshly ground black pepper, and the juice from half of a small lemon, plus more to taste.
Stir the cooked shrimp back into the pot before dishing into bowls. Garnish with the remaining sliced green onions and minced fresh parsley if desired.