Hard-boil eggs (see Tip). Peel when cool enough to handle. Set aside one of the yolks for the dressing. Coarsely chop the remaining eggs.Advertisement
Meanwhile, heat 1 teaspoon oil in a large nonstick skillet over medium-low heat. Add onion; season with salt and pepper. Cook, stirring often, until very tender and light golden, 10 to 20 minutes. (Add 1 to 2 tablespoons water if onions are browning too quickly.)
Cut baguette into 4 equal lengths. Split each piece in half horizontally. Pull out the soft bread from the center of each piece, leaving 1/2-inch-thick shells. Place soft bread in a food processor or blender and process to form fine crumbs. Measure out 1/2 cup of crumbs (reserve the rest for another use).
Mash garlic with 1/4 teaspoon salt with the side of a chef's knife. Transfer to a medium bowl. (Alternatively, mash garlic and salt in a mortar with a pestle.) Add reserved egg yolk and mash with a fork. Whisk in mayonnaise, lemon juice, mustard, anchovy paste and remaining 1 teaspoon oil. Fold in parsley, olives, reserved chopped eggs and breadcrumbs. Season with pepper.
To assemble sandwiches, spread the caramelized onions over the bread-shell bottoms. Mound the egg mixture over the onions. Top with mesclun (or lamb's lettuce) and replace bread tops.
Make Ahead Tip: The sandwiches will keep, wrapped in plastic wrap, in the refrigerator or in a cooler with a cold pack for up to 8 hours.
Ingredient note: You can make your own mesclun by combining your choice of tender greens, both bitter and mild.
Tip: To make hard-cooked eggs: Place eggs in a single layer in a saucepan; cover with water. Bring to a simmer over medium-high heat. Reduce heat to low, cover and cook at the barest simmer for 10 minutes. Pour off hot water and run cold water over the eggs until completely cooled. To peel, crack the shell, then roll egg between your palms to loosen shell. Peel, starting at the large end. Rinse under cold water or dip in water to remove bits of shell.
1/2 vegetable, 1/2 medium-fat meat, 1 fat