Make the focaccia: Line a 9×13-inch pan or rimmed baking sheet (I take advantage of these however mine are very previous) with a big piece of parchment paper that extends up the edges, pressed in. Drizzle parchment with 3 tablespoons olive oil and scrape risen dough onto it. Making an attempt to not press any air out of the dough, use your arms, sliding them beneath a little bit, to softly stretch the dough a few times in direction of the sides. No must make it fill out the pan fully; it can get there by itself because it rises once more. You probably have one, coat a second 9×13-inch pan or rimmed baking sheet with olive oil and upend it over the focaccia pan to behave as a lid for the rise. (If you happen to don’t have one, use one other giant baking dish, like a lasagna pan. The dough wants room to develop.) Put aside for one more 1 1/2 hours.
45 minutes to 1 hour later, put together the toppings: Place sliced zucchini in a single bowl and toss it with 1/2 teaspoon kosher salt. Put aside. Place sliced potatoes in a second bowl and toss them with 1 teaspoon kosher salt. Put aside. [This will soften the vegetables so they cook nicely.]
Assemble focaccia: Warmth oven to 450°F. Drain zucchini and pat it dry on paper towels. Do the identical with the potatoes. Fastidiously take away the pan overlaying the focaccia dough. Don’t fret if the dough seems to be about to spill over the edges; it’s precisely proper. Cowl the focaccia dough with shingles of drained zucchini and potatoes (plus salami, if utilizing), then sprinkle with rosemary needles, to style. Drizzle focaccia with remaining 2 tablespoons of olive oil and use your fingertips to dimple the dough a number of occasions — maybe 20 finger impressions whole. Resist over-dimpling or the focaccia turns into even, flat, and boring. Sprinkle throughout with flaky sea salt.
Bake focaccia: For 30 to 38 minutes, or till a deep golden brown on high and on the edges. Control it for the final 8 minutes and check out to withstand pulling it from the oven too quickly. When it doesn’t brown sufficient, the sides soften too quick.
Switch to a cooling rack and let cool for five minutes, for those who can bear it. Slide the focaccia out of the pan and minimize into squares [especially if you’re taking it somewhere; don’t you hate cutting up food on a picnic blanket with a plastic knife?]. Take pleasure in!
Leftover focaccia retains at room temperature for a number of days. Rewarming it in a 350-degree oven helps re-crisp the highest.
