Piquillo peppers are a specific type of sweet pepper grown in Navarra, in the southern part of the Basque Country in Spain. Roasted red peppers could be used as a substitute, but are usually much larger than piquillo peppers. Makes 28 peppers For the Peppers 2 cups whole milk 2 cups half-and-half 1 tablespoon unsalted butter 1 tablespoon olive oil 1 small onion, finely chopped 9 ounces chopped frozen spinach, thawed 3/4 cup flour 1 tablespoon salt 2 8-ounce jars roasted whole piquillo peppers, drained and patted dry For the Sauce 1 tablespoon olive oil 2 cloves garlic, thinly sliced 1 4-ounce can tomato sauce 1/4 cup white wine 1 teaspoon salt 1 teaspoon sugar 1/4 cup fresh parsley, chopped Prepare the peppers: Combine the milk and half-and-half in a pot over low heat. Heat to a slight simmer. Heat the butter and olive oil in a thick-bottomed skillet over …