Combine the lemon zest, fresh lemon juice, chopped fresh basil, paprika, salt, crushed red pepper flakes, black pepper and minced garlic in a medium bowl. Whisk in 3 Tablespoons of olive oil. Set the bowl aside. Place the remaining 1 Tablespoon of olive oil in a large skillet over medium high heat. Add the shrimp to the skillet. Cook the shrimp for 2 minutes. Add the ingredients we whisked together in the bowl - to the pan. Cook the shrimp another 2 or three minutes until cooked through. The shrimp is cooked through when they turn pink in color with bright red tails. Remove the cooked shrimp from the skillet to a plate.Place the romaine lettuce and trimmed watercress in a large bowl. Add the diced avocado, and tri colored cherry tomatoes to the bowl. Add the cooked shrimp to the bowl and toss the ingredients together. Divide the salad between 4 dinner plates and serve.