Veggie Gravy for Biscuits

Ingredients

• 4 Tbsp. unsalted butter, divided
• 2 Tbsp. extra-virgin olive oil
• 1 small yellow onion, diced small
• 8 oz. cremini mushrooms, stems removed, diced small
• 1 large carrot, peeled, grated
• 1 small zucchini, grated
• 4 large cloves garlic, minced
• 3 Tbsp. all-purpose flour
• 2 cups low-sodium vegetable broth
• 1/2 tsp. kosher salt, divided
• 1/2 tsp. dried thyme
• 1/2 tsp. ground black pepper
• 2 Tbsp. nutritional yeast
• 1/2 cup plant-based milk, such as soy or oat
• 1 tsp. apple cider vinegar