Preheat a large pot over medium-high heat, add oil and sausage and cook until lightly browned (about 2 minutes). Fill pot with the cooked sausage with water until pot is two-thirds full. Add most of the seafood seasoning, reserving a tablespoon for later. Bring the contents of the pot to a boil. Add the potatoes and cook for 10 minutes or until the potatoes are 3/4 done. Add corn and cook for 4 minutes. Add shrimp and cook until shrimp are cooked through, 2 to 3 minutes. Drain all ingredients and place the shrimp boil ingredients on a platter. Lightly season with the remaining seafood boil seasoning mix. Garnish the shrimp boil platter with the diced tomato and parsley. Serve the shrimp boil with lemon wedges, melted butter and hot sauce.