Bring a large pot of salted water to boil. Blanch the nettles in the pot for 2 minutes. Remove from pot and soak in ice bath to stop the cooking process. Using paper towel, squeeze out excess water from nettles.
Place nettles, garlic, pine nuts, lemon and cheese in food processor. Pulse until mixed. While running, slowly drizzle in olive oil. Mix until sauce forms. Store in refrigerator for up to 2 weeks before using.
For the sandwiches...
Whisk together the eggs and milk. Melt butter in large skillet over low heat. Add eggs and stir constantly as they cook. Remove from heat when eggs are just set. Do not over cook.
Heat griddle or bbq to medium-high heat. Spread mayo over both sides of bread. Place 8 slices of bread across heat source. Top with cheese. Cook until cheese starts to melt. Add proscuitto and then top with eggs and pesto and remaining 8 slices of bread. Flip and cook until other side of bread is well toasted.
Notes
New to Kewpie Mayo? Be prepared to get hooked! This import from Japan is made only from egg yolks and not whole eggs and the only mayo that I use now.