Perfect Turkey Burgers

INGREDIENTS

• Kosher salt and freshly ground pepper
• 1 1/4 pounds 85% to 93% lean ground turkey
• 8 thin slices manchego or white cheddar cheese
• 1 tablespoon coarsely chopped shallot
• 3 tablespoons lightly packed fresh parsley
• 4 English muffins, split
• 1 large portobello mushroom cap
• 1 teaspoon Worcestershire sauce
• Dijon mustard, mayonnaise and sliced avocado, for topping
• 2 tablespoons extra-virgin olive oil, plus more for brushing