Add the diced bacon pieces to a hot skillet, and cook, stirring frequently, over medium heat for about 5 minutes, until the bacon is cooked and crispy. Drain the bacon fat into a heatproof bowl (reserve for other recipes!). Remove the crispy bacon bits into a plate with a paper towel to absorb the extra fat.
Toss the shrimp with the Cajun seasoning in a small bowl, and add to the heated skillet which still has a bit of bacon grease remaining. Cook for 2-3 minutes on each side, or until the shrimp is fulled cooked. Squeeze some lime juice over the shrimp. Set shrimp aside.
Assemble the salad. Place the sliced tomatoes and avocado on top of the spinach. Sprinkle with crispy bacon. Top with cooked Cajun shrimp. Shave some Parmesan over it. Drizzle with cilantro lime dressing.
Cilantro Lime Dressing
In a small bowl, combine the very finely chopped cilantro, juice of 1 whole lime, and 2 tablespoons of olive oil. Grate 1 garlic clove into the dressing, and add 1/4 teaspoon salt and freshly ground pepper to taste. Mix well, squeezing the cilantro into the dressing to release its flavor.
If your Cajun seasoning doesn't have salt, add a generous pinch of salt when seasoning the shrimp with the Cajun seasoning.