Trim excess fat from the pork roast.

In a small bowl, combine minced garlic, ground ginger, dried thyme, marjoram leaves, and pepper.

Rub the spice mixture evenly over the pork roast.

Heat oil in a skillet over medium-high heat.

Brown the pork roast on all sides in the skillet.

Transfer the browned roast to a crockpot.

In a separate bowl, mix together chicken broth, brown sugar, lemon juice, soy sauce, and orange zest.

Pour the juice mixture over the roast in the crockpot.

Cook on low heat for 8-10 hours or on high heat for 4-5 hours, until the pork is tender.

Remove the roast from the crockpot and set aside to rest.

Skim off any excess fat from the sauce in the crockpot.

Measure the sauce. If needed, add water to bring the total volume to 2 cups.

In a small bowl, whisk together cornstarch and orange juice to form a slurry.

Pour the cornstarch slurry into a saucepan along with the sauce from the crockpot.

Cook over medium heat, stirring constantly, until the sauce thickens.

Season with salt and pepper to taste.

Slice the pork roast and serve with the thickened orange sauce.