Tomato Leaf Swiss Meringue Buttercream

Strain through a fine-mesh sieve if you want only the brilliant color and a cleaner finish. Leave unstrained for a speckled, full-flavor experience. (Makes about 2 cups.) Use in the buttercream below, or spoon into vinaigrettes, curds or ricotta piled on toast. Refrigerate immediately in a clean airtight container and use within 3 days, or freeze promptly in small portions for up to 3 months. Never store fresh tomato leaf oil at room temperature.