Keto Chicken & Rice Soup (without cauliflower!)

Ingredients

• 1 rotisserie chicken (about 4 cups shredded, cooked chicken)
• 1/2 cup salted butter (1 stick)
• 1 cup diced yellow onion
• 1 cup sliced carrot
• 1 cup sliced celery
• 1 teaspoon garlic powder
• 1 teaspoon onion powder
• 1 teaspoon salt
• 1/2 teaspoon dried oregano leaves
• 1/2 teaspoon black pepper
• 1 tablespoon arrowroot powder
• 1 cup heavy cream
• 4 cups chicken broth
• 4 oz (1/2 package) lupini rice