Mix the herb butter ingredients until fully combined. Set aside.

In a pan over medium heat, sear the sausages in 1 tsp olive oil for 3 to 4 minutes, turning occasionally.

Add about ¼ cup of water to the pan, then cover the pan and reduce the heat to medium low. Cook sausages, covered, for 7 to 8 minutes.

Remove the cover and cook for another 5 minutes, or until the water evaporates and the sausages reach 160°F with an instant read thermometer. Remove the sausages from the pan and set them aside to rest.

Once rested, slice the sausages into coins.

To the same pan that you cooked the sausages in (keep the drippings for added flavor), add 1 tbsp of butter, along with the peppers and onions.

Season the veggies with salt, garlic powder, and pepper, and sauté until soft, about 20 minutes.

Add the sliced sausages back to the pan, toss with the peppers and onions, and cook for a couple more minutes to heat them back up.

Spread some herb butter onto both sides of a hoagie roll. Top with the sautéed sausage, peppers, and onions and garnish with parsley, if using.

If you’re making the herb butter ahead of time, form it into a log and wrap it in plastic wrap, parchment paper, or wax paper and place in the fridge. About 10 minutes before you’re ready to use it, remove it from the fridge to soften.