To a deep-sided skillet, add enough vegetable oil to fill 1 ½ inches deep. Heat over medium-high until the oil reaches 375 degrees F.
To a medium mixing bowl, add the flour, baking powder, and salt and whisk to combine. Pour in the milk and mix with a spatula until a dough forms. (The dough may feel rough. If it's too wet, add a little more flour.)
Turn the dough out onto a floured work surface. Knead the dough for about 5 minutes, this will smooth the dough and allow it to stick together fully. Then allow the dough to sit for 5 minutes.
Cut the dough into 6 pieces and then roll each piece into a ball. Use a rolling pin or your hand to flatten each ball into a dough circle no thicker than 1/8 inch.
Place a dough circle into the hot oil and cook for 1 minute on each side until the fry bread is golden and puffed up. Transfer to a paper towel-lined baking sheet or tray. Repeat with the remaining dough.
If there are any large air bubbles on the fry bread, use a spatula or your hands once cooled to the touch) to flatten them down.
Spread a layer of refried beans (about 2 TBSP) on each fry bread. Then top with taco meat or ground beef, shredded cheese, lettuce, and tomatoes. Add a dollop of sour cream and/or cilantro if you like. Serve warm or at room temperature.