I've been experimenting with kebab seasoning lately, and I'm stuck on trying to amp up the flavor.

I've tested this recipe using ground pork shoulder with some additional fat added to the mixture, then I used Activa RM to bind the mixture in order to form a cylindrical sausage shape. After slow poaching to firm up, I then gave it a quick pan sear to obtain some color. However, the end product still ends up a bit dry.

A few thoughts, after my own recent experiments with spice mixes: are you adding enough salt? I sometimes add salt directly to my spice mix, but other times salt the meat first (so I can get the right amount), then apply the spice mix on top. When I don't use enough, the overall flavor is lacking so maybe that's the culprit? And then of course the freshness of your spices will make a huge difference, especially the ones you're using in largest quantity. For cumin and coriander, I'd recommend freshly grinding it since the pre-ground stuff loses its flavor so quickly.

Depending on what meat you are skewering you might think about a marinade of yogurt. The enzymes help tenderize the meat and add a tang to it. Works well with chicken or lamb. I see nothing wrong with your spice mix but amping up the heat doesn't add the "backbone" that you are after.

It's not exactly a spice, but you could try incorporating lime at some point to get some acid... I love spicy foods and find that an acid often serves to clarify and emphasize the individual flavors of a rub or marinade. I wish I could find a link, but a while a back I saw a recipe somewhere that called for doing multiple half-portion skewers that were each rubbed with one of three spices (I remember cumin and oregano but not the third one). The idea was that the flavors still get a chance to mingle when eaten together, but each element has a chance to shine on its own. I never tried it but it stuck with me.