In a mixing bowl, combine minced shallots, sherry vinegar, kosher salt, grapeseed or canola oil, and chopped cilantro. Stir gently to create a broken vinaigrette. Taste and adjust with additional salt and freshly ground black pepper.

Preheat the fryer oil to 175°C (350°F). Spray metal cannoli molds with nonstick spray. Wrap a potato slice around each mold, pinning the seam against the side.

Place in a taco frying basket and fry until golden and crisp, approximately 2–3 minutes. Drain the shells on absorbent paper, cool slightly, and carefully slide them off the molds. Repeat until all potato slices are fried.

In a saucepan, bring boiling water, butter, and salt to a simmer. Remove from heat and stir in the milk.

Gradually incorporate instant mashed potatoes, folding in the grated parmesan and nutmeg until smooth and creamy. Adjust the consistency with additional hot water or milk as needed.

Transfer the mashed potato filling to a pastry bag. Pipe the filling into each cooled potato shell promptly to prevent softening.

Arrange the filled cannoli on serving plates. Spoon salsa verde over the cannoli or around the plate. Garnish with freshly ground black pepper, flaked salt, and additional shaved parmesan if desired.