Heat olive oil in a large skillet over medium heat. Add onions, garlic and jalapenos; saute until slightly softened, about 3 minutes. Add shredded pork and cook until heated through, about 3 minutes. Set aside.
Preheat the broiler setting on your oven.
Lay flour tortillas on a large cookie sheet (Note: depending on the size of your cookie sheet you may need to do these 2 at a time). In the center of the tortilla, layer, in this order: refried beans, pork mixture and pepper jack cheese. Place under broiler for 2 minutes or until cheese starts to melt. Remove from oven and top with guacamole. Roll into a burrito.