Set your Instant Pot to saute and add the oil to the pot. Sprinkle beef with salt and pepper. Working in batches as needed, brown the beef on all sides. (If you're in a rush, you can skip this step.)
1 tablespoon avocado oil, 2 lbs. stewing beef, 1 teaspoon each: sea salt and pepper
Add the tomato paste to the pot and let it caramelize for 3-4 minutes, or until it has darkened and is sweet smelling.
6 ounce can tomato paste
Add the carrots, onion, mushrooms, baby potatoes, beef stock, thyme, and bay leaves to the pot and stir. Lock the lid and set the Instant Pot for 35 minutes on High Pressure. When it has finished cooking, use the quick release to release the pressure for at least 5 minutes.
4 large carrots, 1 medium onion, 1 lb. mushrooms, 1 lb. baby potatoes, 4 cups beef stock, 2 teaspoons dried thyme, 2 bay leaves
Sprinkle the agar powder over the stew and stir to thicken.
1 teaspoon agar powder
While the stew is cooking, prepare the pesto. Place all the pesto ingredients into a blender and blend on high until mostly smooth. If needed, you can add a little water to thin the pesto. Serve spooned over the top of the beef stew.
2 ounces spinach, 1 green onion, Juice from 1 lemon, ⅓ cup slivered almonds, ¼ cup olive oil, 1 small garlic clove, ½ teaspoon salt
Notes
Agar powder is a powder made from seaweed that does an excellent job of thickening liquid. You can find it at most health food grocery stores (like Whole Foods or Trader Joes) or you can buy it online here.