Last summer I designed a vegan/ vegetarian menu for a new vegetarian cafe in Saint Louis. I created a line of vegetarian sausages that are well receipted by the vegan/veg community.
I used a vital wheat gluten base (seitan) and used A TON of spices and fresh herbs. The gluten absorbs flavor really well. For our summer sausage bbq plate, I used a wheat gluten base, lots of spices and herbs and for the liquid portion I used veggies stock, soy sauce, mirin and sometimes apple cider vinegar or apple juice.
I portioned 8 ounce servings of the wheat gluten/ spice mush, tightly wrapped it them in cheesecloth and manipulated the shape i wanted (tightly tying off the ends creates a rustic, realistic sausage shape and feel). Then i baked those in a bath of salted water or soysauce and water. Those were baked at 375 for about hour and a half. Until the sausages were firm and springy when touched.
After the boiling process, i would unwrap the sausages and smoke them outside on a shitty smoker with applewood chips. Then they were held for service, where they would be seared on the flattop, cut up for vegan gumbo or shredded for vegan tacos.
My breakfast sausage was made the same way, expect i made a larger round loaf with fresh shredded apples and maple syrup. After broiling, the loaf would be kept whole and sliced right before service. Those slices (representing a jimmy dean sausage patty) would then be seared to order.
Making your own seitan is a total money maker. You can recreate almost any meat product and manipulate the flavors as you wish. Ive used it to make "chicken cutlets", Al Pastor, "duck" and a meat substitute for banh mi's.
I hope I was able to help!