Sous Vide Tender Beef Quesadilla

Ingredients

• 10 ounces (300g) brisket beef
• 1 white onion, roughly chopped
• 2 carrots, roughly chopped
• 1 stalk celery, roughly chopped
• 4 tablespoons unsalted butter or extra virgin olive oil
• 4 sprigs thyme
• 2 cloves of garlic
• 1 bay leaf
• 4 large flour tortillas
• 1 cup grated cheddar cheese
• 4 tablespoons sour cream, for serving
• 4 tablespoons salsa, for serving