Fill a medium pot with water and 2 teaspoons of salt. Bring to a boil over high heat.
Peel potatoes and chop into 4 pieces each. Carefully lower potatoes into the boiling water. Boil for 15-20 minutes or until fork tender.
Turn off the heat. Strain the water from the potatoes and place the potatoes back into the empty pot.
To the pot, add the butter, 1 teaspoon salt, ½ teaspoon garlic powder, ½ teaspoon onion powder, pepper and broth. Use a potato masher to mash everything together until mostly smooth.
In a medium fry pan, add olive oil, sliced peppers and ¼ teaspoon salt. Saute on medium-high heat for 6-8 minutes until lightly charred. Scoop veggies out of the pan and transfer to a bowl or plate.
Add remaining 1 teaspoon of oil to the pan, and add the black beans, ½ teaspoon salt, ½ teaspoon garlic powder, ½ teaspoon onion powder, chili powder. Cook for 3-5 minutes, on medium-low heat, stirring occasionally until warmed through.
Optional: Reheat the mashed potatoes if they are no longer warm over medium heat, and add 1-2 tablespoons more broth if needed to thin out the mixture. Mix all together.
Transfer the warm potato mixture to a large serving bowl or two individual bowls.
Top with a layer of sour cream, sauteed peppers, cooked black beans, scallions, and parsley or cilantro. Add radish as garnish if you desire too. Enjoy right away!