Cut the muffin in half, and lightly toast it.
Grease the inside of a food ring (if using), and heat the remaining oil in a frying pan. Crack the egg into the ring, or directly into the pan if not using a ring. Cook over a fairly low heat for about 5 minutes, until the white is mostly cooked through. Remove the ring, then flip the egg for just a couple of seconds, to make sure the white is cooked on top. Leave the yolk runny if you can.
While the egg is cooking, place the cheese slice on one half of the muffin.
Cook a spoonful of refried beans for a few seconds in the microwave if you'd prefer them to be hot, then add them to the muffin on top of the cheese slice.
Mash the avocado flesh, and spread it onto the other half of the muffin.
When the egg is cooked, place it on top of the refried beans, and add a dash of hot sauce. Sandwich the two halves together, and serve warm.