Prep the avocado so it stays bright: halve and pit the avocados, scoop the flesh into a bowl and keep one avocado pit in the bowl if you’ll wait a short while — it slightly slows browning. Mash with a fork until mostly smooth but still a little chunky; this texture lets small pockets of avocado remain so each bite has cream and body. Rationale: over-whipping gives a gluey paste; light mashing keeps mouthfeel and visual appeal.

Season the avocado: add 1/4 tsp kosher salt, 1/4 tsp freshly ground black pepper, the zest of 1 lemon and a squeeze (about 1 tsp) of the 1/2 lemon if you like a brighter note. Mix gently. Rationale: salt and acid open up the avocado’s flavor — zest gives aromatic oils that lift the dish without extra liquid, while a small amount of lemon juice prevents oxidation and adds brightness.

Preheat your skillet or toaster: if using a skillet, heat over medium-high for 1–2 minutes; if using a toaster or oven broiler, preheat accordingly. Rationale: starting with a hot surface ensures the bread toasts quickly to a crisp exterior without drying out the interior.

Toast the bread: brush both sides of each slice lightly with 1/2 tsp olive oil (or melt 1/2 tbsp butter per two slices for a richer finish). Place the bread in the hot skillet and cook 1–2 minutes per side until golden brown and crisp — you want a toothsome crust that will stand up to the avocado and salmon. Rationale: oil or butter encourages even browning, and a properly toasted base contrasts with the soft avocado and silky salmon, preventing sogginess.

Warm the smoked salmon briefly (optional): if you prefer a slightly less icy salmon, lay the slices on a plate and set in the warm (turned-off) skillet for 30–60 seconds to take the chill off. Rationale: gently tempering the salmon highlights its oil and aroma without cooking it; do not sauté or heat over high heat, as smoked salmon should remain essentially raw to preserve texture and flavor.

Assemble the toasts: spread a generous layer (about 1/3 cup) of the mashed avocado on each warm slice, pressing lightly to adhere. Top each with 3 oz / 85 g smoked salmon (arrange in loose folds so it looks voluminous). Rationale: pressing the avocado onto warm toast helps it stick; folded salmon creates texture and air pockets that catch lemon and olive oil.

Finish with bright, briny accents: scatter drained capers (about 1 tbsp per toast) over the salmon if using, sprinkle a little extra lemon zest, a few grinds of black pepper, and drizzle the remaining 1/2 tsp olive oil across both toasts (lightly). Add chopped dill or chives if desired. Rationale: capers add a briny counterpoint to the creamy avocado and smoky salmon; finishing olive oil adds gloss and mouthfeel, while fresh herbs and zest amplify aroma.

Plate and serve immediately: serve each portion right away while the toast is still crisp. If making ahead for a brunch buffet, keep avocado mixture refrigerated and toast right before serving. Rationale: the contrast between crisp toast and soft toppings is essential — waiting too long will soften the bread and degrade the texture.