How to Make It
In a medium saucepan, heat the 1/2 cup of olive oil. Add the dried shiitakes and garlic and cook over moderately low heat, stirring, until softened, about 3 minutes. Add the crushed tomatoes, kombu and sugar and simmer until thickened slightly, about 30 minutes. Strain the pomodoro sauce through a fine-mesh sieve set over a medium bowl, pressing on the solids; season with kosher salt. Let cool to room temperature.
Meanwhile, preheat the oven to 350° and line a large rimmed baking sheet with parchment paper. In a food processor, pulse the panko, flour and cocoa powder until combined. Add the olives and pulse until finely chopped. Add the butter and pulse until the mixture resembles coarse crumbs. Spread the streusel on the prepared baking sheet. Bake for about 15 minutes or until toasted and golden brown. Transfer to a rack and let cool completely.
Spoon some of the pomodoro sauce onto a platter or plates. Arrange the tomato slices over the sauce and top with the burrata. Generously sprinkle with the olive streusel and garnish with basil leaves and fennel fronds, if using. Drizzle the salad with olive oil and sprinkle with sea salt before serving.
Kombu (dried seaweed) is available at Whole Foods and from amazon.com.