Smothered Pork Roast Over Rice

Ingredients

• 1 (6- to 7-pound) boneless pork roast (shoulder or butt)
• kosher salt
• ground black pepper
• 2 large onions, thinly sliced
• 8 garlic cloves, thinly sliced
• 3 tablespoons fresh thyme leaves
• 1 tablespoon dried rosemary, crumbled
• 2 tablespoons vegetable oil
• 8 tablespoons (1 stick) butter
• 1/2 cup all-purpose flour
• 4 cups chicken broth
• juice of 1/2 lemon (optional)
• steamed rice (for serving)
• chopped parsley (for garnish)