Pork Sausages with Apple Onion Gravy and Champ

Ingredients

• 1 tablespoon olive oil
• 1 pound pork sausages (like bangers or other savory pork sausages)
• 3 tablespoons unsalted butter (melted)
• 1 large yellow onion, thinly sliced
• 1 Granny Smith apple, cored and thinly sliced
• 1 tablespoon all-purpose flour
• 1 1/2 cups beef broth
• 1/2 teaspoon dried thyme
• 2 pounds Russet potatoes, peeled and quartered (for Champ)
• 1/2 cup milk, warm
• 4 green onions, thinly sliced, divided
• 1 1/2 cups frozen green peas
• 1 teaspoon kosher salt, divided
• 1/2 teaspoon black pepper, divided