Preheat oven to 200F.

Arrange two oven racks to divide oven in thirds.

Line two baking sheets with parchment paper and set aside.

Place egg whites in a large bowl; beat with a mixer at high speed until foamy.

Add cream of tartar and continue to beat until soft peaks form.

Gradually add sugar, 1 tablespoon at a time, beating until egg whites are shiny and stiff peaks form. DO NOT overbeat.

Add vanilla and beat until incorporated.

Pipe or spoon 24 (2-inch-round) mounds onto previously prepared baking sheets.

Place in oven and bake for 2 hours, rotating pans halfway through cooking.

Turn oven off and Cool meringues in oven 40 minutes to 1 hour. (Meringues are done when surface is dry and meringues can be removed from paper without sticking to fingers.)

Remove from oven and carefully remove meringues from paper.

Combine chopped chocolate chips and vegetable oil in a small microwave-safe bowl.

Melt chocolate in the microwave for 40 seconds to 1 minute, or until melted and smooth.

Dip half of each cookie in melted chocolate.

Let any excess chocolate drip off before placing on a baking sheet lined with wax paper.

Allow to set at room temperature; do not put in the fridge.

Once set, serve or store in an airtight container.