White Castle now sells a veggie burger, The Impossible Slider

A pilot program began in April at White Castle sites in New York, New Jersey and Chicago. The herbal burger will now be sold in 377 sites in 13 states.

The Burger Impossible launched in 2016 and quickly began to make its way onto the restaurant scene. It is now sold in more than 2,000 restaurants across the country, according to Impossible Foods.

The burger looks like a hamburger. It smells, sizzles and cooked like any other. You can cook it as you wish.

According to impossiblefoods.com, it is made from natural ingredients such as wheat and potato proteins, coconut oil for fats, a soy sauce fillet and apples from Earth. The company says the flavor is associated with "konjac and xanthan – common ingredients in chefs' cuisines".

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But the kicker is the color. The galette is red, as is the ground beef. It even bleeds in red as a typical medium-rare cooked burger would be.

The color and texture come from an ingredient called heme, a component of many proteins, including hemoglobin – the pigment that gives color to blood. Heme is found in both plants and animals, and Impossible Foods starts with heme from the roots of soybean plants.

Although Impossible Burger is ideal for plant-based diets, the launch of White Castle is designed to capture the appetite of beef lovers.