Combine sage, rosemary, thyme, tarragon, salt, olive oil, garlic, and lemon zest in a small bowl.
Spread over pork roast and let marinate for at least 30 minutes, up to overnight.
Preheat oven to 425 degrees F.
Place pork roast in roasting pan or dutch oven.
Place diced potatoes, sliced onion, and brussels sprouts alongside the pork in the roasting pan and dutch oven and drizzle with olive oil.
Season with salt.
Roast in oven for 15 minutes.
Reduce oven temperature to 350 degrees F and roast another 45-60 minutes, until the internal temperature of the pork reaches 145 degrees.
Remove from oven and let rest for 15 minutes.
Slice pork into ½” slices.
Serve with potatoes, onions, and brussels sprouts.
Enjoy!