Pat the shrimp dry on paper towels and season lightly with 1/4 teaspoon kosher salt and a few grinds of black pepper. Drying the shrimp removes surface moisture so they sear quickly and develop a slightly caramelized exterior rather than steaming.

Make the quick marinade: in a small bowl whisk together the minced garlic, lemon juice, 1/2 tablespoon of the olive oil, and half the chopped herbs (reserve the rest for finishing). Toss the shrimp in the marinade for 5–8 minutes. The acid brightens the shrimp and the brief marinate time (not more than 10 minutes) seasons without 'cooking' the shrimp's delicate texture.

Toast the sourdough: heat a skillet or grill pan over medium-high heat. Brush the bread lightly with the remaining 1/2 tablespoon olive oil and toast both sides until golden and crisp, 1–2 minutes per side. Toasting on a hot pan gives the bread a sturdy, slightly charred base that won’t go soggy under the succotash.

Prepare the corn succotash base: in the same hot skillet, add a tiny splash of oil (or a quick wipe of the pan if oily), then add the fresh corn kernels over medium-high heat. Season with a pinch of salt. Cook, stirring occasionally, until the kernels show a few golden-brown charred spots, about 3–4 minutes. Browning the corn concentrates its sugars and adds nutty, roasted notes.

Turn the heat to medium and add the diced cucumber and halved cherry tomatoes to the skillet with the corn; toss for 30–45 seconds just to warm and marry the flavors but maintain a bright, crisp texture. Overcooking the cucumber softens it and loses the fresh crunch that contrasts the warm corn and shrimp.

Season the succotash: remove from heat, stir in a pinch more salt, a grind of pepper, and the leftover chopped herbs. If you like, add a small squeeze of lemon to brighten. Set the succotash aside on a plate and wipe the skillet clean if there's any residue.

Sear the shrimp: return the skillet to high heat and add a teaspoon of oil if needed so the pan is slick. Add the shrimp in a single layer and sear undisturbed for about 1–1.5 minutes per side until opaque with a faint char (shrimp cook very quickly). High heat gives the shrimp a quick sear that locks in juices and adds a touch of caramelization — avoid crowding the pan to maintain that sear.

Finish the shrimp: remove the pan from the heat and toss the shrimp with any leftover marinade juices in the bowl and a light pinch of salt to taste. Let them rest 30 seconds — they will carryover-cook slightly and stay tender.

Assemble the toast: rub the warm toasted sourdough lightly with the cut side of an optional garlic clove (this mellows raw garlic and aromatizes the bread). Spoon a generous layer of the warm corn & cucumber succotash onto the toast, top with the grilled shrimp arranged attractively, and finish with a drizzle of olive oil, a sprinkle of chopped herbs, a pinch of flaky sea salt, cracked black pepper, and a bit of lemon zest if using. The warm succotash slightly warms the toast while the tender shrimp make each bite luxurious.

Serve immediately while the toast is crisp and the shrimp are warm. Explain to diners that the best contrast comes from the hot-cold textures and the bright acid finishing the dish.