Preheat the oven to 400°F.

Heat the vegetable oil in a medium pan over medium heat. When the oil is shimmering, add the onion and cook until translucent, about 3 minutes. Add the garlic and cook until fragrant, about 1 minute more.

Add the ground beef and season with the salt, pepper, and mustard powder. Break up the meat with a spatula, then cook without disturbing for 3–5 minutes, until the beef browns. Drain any excess liquid from the pan.

Add the ketchup and Worcestershire sauce. Stir until the meat is fully cooked and the sauce is evenly distributed, about 3 minutes more. Remove the mixture from the heat and transfer to a medium bowl. Set aside.

Line 2 baking sheets with parchment paper.

Lay the thawed puff pastry sheets on a flat surface lined with parchment paper. Using a 3-inch heart-shaped cookie cutter, punch out 9 hearts per sheet. You should have 36 total.

Transfer 18 of the hearts to the prepared baking sheets. Spoon about 1 tablespoon of the beef mixture into the center. Brush the edges of each cut-out with the beaten egg, then place an ice pop stick at the bottom of each heart, ensuring that about ⅓ of the stick is wedged into the beef filing and the rest is hanging out from the bottom of the heart.

Gently lay the remaining 18 cut-outs over each of the filled hearts. With a fork, carefully crimp the edges together all around to seal, ensuring the beef mixture doesn’t seep out onto the edges.

Once all are sealed, brush egg wash over the tops of each sloppy joe and then sprinkle the cheddar cheese on top.

Bake for 15 minutes, or until the pastry is puffed and golden.

Garnish the sloppy joe sticks with green onions, then serve with sour cream, potato chips, and pickles.