Boil potatoes in salted water for 10 minutes, until soft but not water-logged. Drain, allow to cool 10 minutes, and mash to a somewhat smooth consistency. Add the egg, anchovies, scallions, 4 tablespoons oil, lemon juice, thyme and salt and pepper, to taste.
Pick through open zucchini flowers to remove stamens and check for bugs. Using a small teaspoon, stuff each blossom with 2 teaspoons of the filling.
In a 10 to 12-inch non-stick saute pan, heat the olive oil until smoking. Place 4 flowers into the pan at a time and cook until golden brown on both sides. Season with salt and pepper.
Arrange 3 blossoms on each of 4 warmed dinner plates and serve immediately, with bruschetta drizzled with best-quality extra-virgin olive oil, and lemon wedges.