Preheat the oven to 350°F and line a baking sheet with parchment paper.
Pulse the bread pieces in the food processor until crumbly. For fine breadcrumbs, pulse more, for coarse breadcrumbs, pulse less.
Spread the crumbs on the baking sheet. Drizzle with the olive oil and sprinkle with salt, and bake 10 to 18 minutes, tossing halfway, until golden brown and toasted.
Combine the lemon zest and cheese at the bottom of a large bowl. Add the breadcrumbs as they come out of the oven and toss. Taste and add any additional seasonings you like.
