Turkey and prosciutto panini with sage. (Photo, Sian Richards.)
2 1/2 tsp
, 1/2-in. thick
, cut into 16 slices
WRAP a damp kitchen towel around the base of a large bowl (to prevent it from slipping). Combine egg yolk, lemon juice, 1/2 tsp Dijon and salt in bowl. Whisk until frothy, about 30 sec. Gradually drizzle in 1 cup olive oil, continuing to whisk. Whisk until mixture thickens to a spreadable consistency, 1 to 2 min. You should have 1 cup mayo. Measure out 1/2 cup and refrigerate up to 3 days for another use. Stir remaining 2 tsp Dijon into remaining 1/2 cup mayo.
SPREAD each bread slice with mayo mixture. Divide arugula among 4 bread slices. Top each with 4 turkey slices, 3 prosciutto slices and 3 sage leaves. Top with remaining bread. Brush both sides of sandwiches with 2 tbsp olive oil.
PREHEAT grill pan or panini press over medium-high. Lay 2 sandwiches on grill pan. Press down with the bottom of another pan until grill marks appear, 1 min. Flip and continue grilling, 1 more min. Repeat with remaining sandwiches. Serve warm.