Prepare the Grits:

1. In a medium-sized saucepan set over high heat, bring the water to a boil. Slowly whisk in the grits and salt until incorporated. Reduce heat to low and simmer, stirring occasionally, until the grits are soft and have absorbed most of the water. Stir in the parmesan, butter and pepper. Taste and adjust the seasoning with more salt and pepper, if desired. Remove from heat and cover to keep warm while you prepare the shrimp.

Make the Shrimp and Fiddleheads:

1. Meanwhile, season the shrimp with salt and pepper.
2. If adding fiddleheads, prepare them by brushing lightly and trimming the woody stems. Wash well under cold running water to remove any dirt or particles. In a large pot of boiling salted water, blanch the fiddleheads for 5 minutes, or until bright green and tender. Drain, then plunge immediately into an ice bath to stop the cooking process.
3. In a large skillet set over medium-high heat, melt the butter until it starts to sizzle. Add the shrimp, garlic and cayenne along with the blanched fiddleheads (if using), and saute for 3-5 minutes or until the shrimp are pink and opaque in the centre. Remove from the heat and stir in the water, lemon juice and parsley. Toss to coat the shrimp with the sauce.
4. To serve, spoon the grits into 4 shallow bowls, and top off with shrimp and sauce. Sprinkle with a little more parsley, if desired, and serve immediately.