Heat the oil in a medium skillet over medium-high heat. Add the onions and cook, stirring, until softened, about 5 minutes. Add the garlic and cook, stirring, until fragrant, 30 seconds. Add the ground beef, seasoning mix, salt and pepper, and cook, stirring and breaking up any clumps, until brown, 3 to 5 minutes. Add the ketchup, tomato paste and Worcestershire sauce and cook, stirring, 1 minute. Add 3/4 cup water and simmer, stirring occasionally, until most of the water has evaporated, about 4 minutes. Stir in the parsley and season with salt and pepper. Transfer to a bowl and let cool to room temperature.
Unroll the tubes of crescent dough but do not separate along the perforations. Pinch the seams of two of the triangles together to make a rectangle and then cut that rectangle off from the rest of the roll at the seam. Repeat with the remaining dough.
Lay the rectangles of dough out on a work surface and cut each in half to make 2 squares. You will have 16 squares. Put 1 rounded tablespoon of the sloppy joe filling in the center of each. Mound a rounded 1/2 teaspoon of Cheddar on top of the beef (there will be cheese leftover). Gather the edges of the dough up over the filing to make a little pouch and pinch to seal each edge. Arrange the pouches on a parchment-line baking sheet and mound a little cheese on top of each.
Bake the pouches until the dough is golden brown and cooked through, about 20 minutes. Serve warm.