Toss the florets from 1 head Romanesco with olive oil, salt, ground cumin and pepper. Roast on a preheated baking sheet at 450 degrees F until browned, about 25 minutes. Pulse 2 cups cilantro, 3 tablespoons unsalted roasted pepitas, the zest and juice of 1/2 lime, 1 small garlic clove and 1 tablespoon water in a food processor. Pulse in 1/4 cup olive oil; season with salt. Spoon on top of the Romanesco; top with more pepitas.