Scrub the skins to remove any traces of soil or dirt. Pat dry.
Line a baking sheet with parchment paper or foil. Sometimes sweet potatoes will release their juices during baking. These will drip and caramelize on your pan. Lining your pan makes for easy clean-up.
Poke the potatoes with a fork four or five times. Pricking them allows the steam to escape so they don't burst. Poking a few holes also reduces baking time.
Oil, yes or no? If you plan to eat the skin (which is full of nutrients) you may want to rub or brush the potatoes with a small amount of olive or avocado oil. Oil adds flavour and will make the skin a little crispy.
Bake until they're tender, about 40 - 50 minutes depending on the size of the sweet potatoes. Insert a fork in the thickest part of the potato. It should go in easily and feel soft.
Black Bean Filling
Sauté onions, then add red pepper and tomatillos. Cook till almost tender, 3 - 5 minutes, then add garlic and cook for one minute longer.
Add black beans and corn and cook for 3 more minutes.
Meanwhile, prepare a quick guacamole. Mash the flesh of one or two avocados, then add lime, juice, cilantro and salt to taste.
Slice open the sweet potatoes. I like to mash the insides a little with a fork to loosen them from the skin.
Fill the insides with the black bean mixture.
Garnish! Top with halved cherry tomatoes, then add a generous dollop of guacamole on top. Done!
If you plan to reheat these, store them covered without the guacamole. Reheat gently in the microwave or in the oven at 350°F. for 15- 20 minutes or until heated through.