Heat broiler to high. Arrange pepper and garlic cloves in a oven-safe frying pan. Place under broiler and cook until charred on all sides, about 8-10 minutes. Remove garlic if it is charred before the pepper.
Place pepper and garlic in a bowl and cover with plastic wrap. Set aside until cool enough to handle, about 15 minutes.
Peel off the charred skin of the pepper and garlic. Core the pepper and cut into small dice. Place 3/4 of the pepper in a food processor fitted with the blade attachment, set the other 1/4 aside for garnish.
Add peeled garlic cloves, black beans, tahini, lemon juice, and salt. Blend until smooth and creamy. Taste and add more salt or lemon juice as needed.
Scrape into a serving bowl and top with reserved red pepper and pumpkin seeds.