Crisp Chopped Bacon: Add bacon in Instant Pot, then heat up Instant Pot using Sauté More function (no need to add oil as bacon has a lot of fat). Stir occasionally and allow the bacon to crisp (~7 - 9 mins). Remove bacon from Instant Pot, then place them on a paper towel to absorb the excess fat. 

Saute Onion, Spices, and Garlic: Add roughly diced onion in the bacon fat, then cook until softened (~3 mins). Then add ½ - 1 tsp chili powder, 1 tsp ground cumin, 1 tsp dried oregano, and minced garlic to Instant Pot. Cook for another minute until fragrant. 
*Spicy Tip: ½ tsp chili powder: a hint of spiciness; 1 tsp chili powder: mildly spicy.

Deglaze Instant Pot: Pour roughly ½ cup unsalted chicken stock in Instant Pot, then deglaze by scrubbing the flavorful brown bits off the bottom of the pot with a wooden spoon. Give it a quick mix.

Pressure Cook Refried Beans in Instant Pot: Add the well-drained pinto beans in Instant Pot, then pour in the remaining 3 ½ cups unsalted chicken stock. Close the lid. Turn the Venting Knob to Sealing Position.
Pressure Cooking Methods:
a) For Tender with Bite Result: High Pressure 40 mins + 25 mins Natural Release
b) For Smooth Tender Result: High Pressure 50 mins + 25 mins Natural Release
After 25 minutes of Natural Releasing, carefully turn the Venting Knob to Venting Position to release remaining pressure. As the Instant Pot is natural releasing, grate the cheddar cheese and thinly slice the green onions.

Drain Beans Liquid: Once the Floating Valve drops, carefully remove the lid. Strain the beans liquid with a strainer. Place the beans back in Instant Pot. Reserve the beans liquid in a mixing bowl.

Mash Beans: Mash the beans with a potato masher or immersion blender until desired consistency. 

Load Instant Pot Refried Beans: Load up your gorgeous Instant Pot Refried Beans with umami bacon bits, thinly sliced green onions, and grated cheddar cheese. Serve & enjoy~