Heat 4 tbsp. extra-virgin olive oil in a large cast-iron skillet over high heat until very hot but not smoking.
Add 1 lb. medium shrimp (about 25 shrimp to a pound) and 6–8 thinly sliced, peeled garlic cloves, then season generously with coarse salt.
Sear shrimp, shaking skillet over heat frequently, until shrimp turn pink and shells are golden and charred in places, 1–1 1⁄2 minutes per side. Squeeze juice from 1 lemon over shrimp, then serve, sopping up the pan juices with the shrimp and pieces of country bread.