I'll post an all time favorite. I wish I had some way of figuring out the nutritional info on this:

5 lbs chicken thighs, deboned (buy a bone-in pack, debone yourself, save the bones for stock)
5 tsp salt
1 container of feta, crumbled
1 lb of spinach, roughly chopped (it looks like a lot, but trust me it'll work)
2 red peppers, seeded, sliced, and roasted with skins removed (you can buy them, but making them is so much fun!) OR a handful of sun dried tomatoes
5 cloves of garlic, minced

Someone told me the best foods have red, white, and green in them. I liked the simplicity of this one, and that it covered meat, cheese, and veggies.

Honestly, it doesn't need other spices but you can add what you want. I used to do this skin off, since thighs had enough meat and chicken thigh meat doesn't really "dry out" like a ground, lean pork would, but many keep it on. Up to you, and how much fat you want. (Probably best to keep it on for keto!) Also, if you don't want the garlic, use garlic salt instead.

Put your chicken in the freezer for a bit on a tray, until it's a little firm to the touch. Thawed chicken in a grinder is super messy.
Grind chicken using a medium plate.
Chop the roasted red peppers or sun dried tomatoes. If you bought them, drain off the oil.
Loosely chop the spinach.
Crumble up the feta.
Mix everything together in a bowl.
Stuff into casings.
Let it sit for at least an hour in the fridge before using or freezing. This lets the flavors meld together, and for the salt to penetrate all the meat.

If you have no grinder or stuffer: 1) combine feta, spinach, and peppers in a food processor and pulse until chopped. Empty into a bowl; 2) Put the chicken into the food processor and pulse until chopped. Then mix everything together. (Never tried, but I imagine it'll work.)

I used to make "burgers" with this sausage and freakin' loved it. I'm looking forward to making it again.