This meal unites two things that've long been staring at each other across the room at each other, just waiting for an introduction: the breakfast standby of quiche and the classic Italian flavors of caprese. Creamy mozzarella, tart tomatoes, and herb-y pesto fill up flaky puff pastries. We're not content to leave it there; a side salad with caramelized shallots on top brings another great union into this meal.
Halve grape tomatoes. Peel and slice shallot into thin rounds. Combine liquid egg, milk, ¼ tsp. salt, and a pinch of pepper in a mixing bowl. Place each puff pastry square in muffin tin and gently lift and press dough into cups. Dough should cover bottoms and sides with corners of each dough square sticking over edges. Refrigerate muffin tin.
Blister the Tomatoes
Place a medium non-stick pan over medium-high heat. Add 1 tsp olive oil and tomatoes to hot pan. Cook undisturbed until slightly charred and skins begin to blister, 2-3 minutes. Season with a pinch of salt and pepper and transfer to a plate. Reserve pan; no need to wipe clean.
Fill and Bake the Quiches
Remove muffin tin from refrigerator. Add half the mozzarella to puff pastry squares. Top with half the tomatoes (reserve remaining for salad) and egg-milk mixture. Top squares with remaining mozzarella. Place muffin tin on prepared baking sheet to catch drips. Bake until dough browns and filling is set (doesn't jiggle when pan is tapped), 20-25 minutes. Rest 5 minutes before carefully removing quiches from muffin tin. While quiches bake, caramelize shallot.
Caramelize the Shallot
Return pan used to blister tomatoes to medium heat. Add 1 tsp. olive oil and shallot to hot pan. Stir often until lightly caramelized, 4-6 minutes. Remove pan from burner.
Toss the Salad
Combine arugula and Italian dressing in another mixing bowl. Season to taste with salt and pepper.
Plate the Dish
Top quiches with basil pesto. Garnish salad with caramelized shallot and remaining tomatoes. Serve quiches alongside salad.