On the sauté setting, heat the vegetable oil. Sauté the poblanos, jalapeño, garlic, and onion until softened, 3–4 minutes. Add the ground beef and salt, and sauté until just cooked, about 4 minutes (stir the meat constantly as it sautés to break it into small pieces). Add the tomato, cumin, and cayenne and sauté for one more minute. Add milk, close the lid on the Instant Pot, and cook under high pressure for 20 minutes. Manually release the pressure.