This dish combines tangy Greek yogurt, sweet corn and fresh herbs in a cool, creamy dip that'll keep you coming back for more. "Milking" the cob is a quick and easy way to make sure you get every last bit of flavor out of fresh sweet corn.
Toss together the baguette, olive oil, 1/2 teaspoon salt and a few grinds of black pepper on a rimmed baking sheet. Bake until the bread is golden brown and toasted, about 10 minutes. Let cool on the baking sheet about 20 minutes; you can store the crostini in an airtight container for up to 2 days.
Meanwhile, use a sharp knife to shave the kernels from the ears of corn and transfer the kernels to a medium bowl.
Once the corn kernels are removed, "milk" the cobs by scraping a butter knife over the them, releasing the remaining milky liquid and letting it drip into the bowl.
Melt the butter in a medium skillet over medium-low heat. Add the onion and cook, stirring occasionally, until soft and translucent, about 5 minutes. Add the garlic and cook until fragrant, about 1 minute more. Add the corn and any milk scraped from the cobs and season with 1 teaspoon salt and a few grinds of black pepper. Increase the heat to medium high and cook, stirring occasionally, until the corn is bright yellow and tender, about 3 minutes. Remove from the heat.
Stir the yogurt, cream cheese, lemon juice and cayenne together in a large bowl until combined. Fold in the corn mixture. Gently fold in the dill, parsley and chives until combined. Refrigerate until cold, about 1 hour.
Transfer the dip to a serving bowl and garnish with the extra dill fronds. Serve the dip chilled with the crostini.