Instant Pot Tuna Casserole

Ingredients

• 3 tablespoons butter
• 1 medium onion (diced)
• 1 cup carrots (sliced)
• 8 oz. sliced white mushrooms (or cremini mushrooms)
• 3 stalks celery (diced)
• 2 cloves garlic (minced)
• 1 teaspoon dried dill
• ½ teaspoon onion powder
• 1 teaspoon garlic powder
• 1 teaspoon dried parsley
• ½ teaspoon freshly cracked pepper
• 1 ½ cups frozen green peas
• 5 cups low-sodium chicken broth
• 2 teaspoons dijon mustard
• 1 ½ teaspoon salt
• 8 oz. egg noodles
• 2 7 ounce cans tuna (albacore or chunk light tuna; Not drained; flaked)
• 1 1/2 cups milk (whole or 2%)
• ½ cup all-purpose flour
• 1 ½ cup shredded cheddar cheese
• Freshly cracked pepper + salt