Line a large baking sheet or pizza pan with parchment paper or nonstick aluminum foil. Place a 4.5-inch diameter bowl upside down in the center of the baking dish and use it as a guide (it will be the center, empty area of your wreath). Arrange triangular sections of the crescent dough on the parchment in a circle around the bowl with the long points facing outward as the "rays" and the wide bases in the center with the edges overlapping. Brush the jalapeño jelly on the dough. Remove the bowl.
In a small bowl, mix the ham, Gruyere and pepper jack, then layer the mixture on the dough, creating a ring around the center of the circle. Pull the points of dough from the outer edge over the filling and tuck under the center rim of the dough circle. The filling will show and that's ok! Top with jalapeño slices all around.
Bake, rotating halfway through, until golden, 20 to 25 minutes. Allow to cool slightly before slicing to serve.