Amazon's Blue Apron knock-off is live — and it's already selling out (AMZN)

Amazon is now selling meal kits that would look familiar to Blue Apron customers — and they're already selling out.

On Tuesday, Amazon began selling kits that contain all the ingredients necessary to cook a selection of meals, including options such as stir fry, burgers, and tacos. Meals — which contain enough ingredients to prepare meals for two to four people — cost between $19.99 and $38.

By 9 am ET on Tuesday, five of the 19 single-meal "Amazon Fresh" options, sold by Amazon but produced by other brands, had sold out.

Amazon is selling brands including Tyson Tastemakers, created by the meat industry giant, and Martha & Marley Spoon, a collaboration between Martha Stewart and meal kit company Marley Spoon. The ecommerce giant is also selling its own brand of meal kits, only available to certain Prime customers.

Amazon Fresh bears a clear resemblance to Blue Apron and other meal kit delivery services. When news broke earlier in July that Amazon had filed a patent for

Unlike many meal kit services, Amazon Fresh meal kits do not require customers to subscribe to a service. Blue Apron, for example, requires customers to sign up for a two or four-person subscription plan to receive ingredients to cook three meals a week.

While Amazon only launched its Amazon Fresh meal kit service on Tuesday, many of the kits have been available for some time. Kits produced in partnership with Tyson, for example, have been available for purchase on Amazon since last year.

"I've tried Hello Fresh, Blue Apron, and another food service that was forgettable enough that I don't remember what the name is. I was only ever wowed by maybe a handful of those meals," one Amazon user wrote in a five-star review of Tyson's Yakisoba Noodle Stir Fry. "This dish was REALLY good and pleased my picky 10 year old son as well! I will buy this again and again!"

Not everyone was as impressed.

"Easy to make but in my opinion, the dish was way, way too salty. And frankly I think it's a little overpriced for what it is," reads one two-star review for the same Tyson stir fry. "There was a smell in my fridge for a couple of days and I think it was either the sauce for the meat? Not quite sure but smell is gone now that the box was removed."