On medium heat in a large skillet, brown the ground chuck, diced onion, jalapenos & garlic. Cook for 5 minutes, then stir in the taco seasoning. Continue cooking until beef is done & onions are soft. Turn the heat down to low; stir in the rinsed black beans.
In a large saucepan, melt the butter. Whisk in the all purpose flour. Cook for 1 minute. Whisk in the milk. Cook, stirring occasionally, until the milk bubbles. Once the milk is bubbling, stir in the shredded cheese until all combined - and sauce is thick & creamy. Remove from heat.
Spread out half a bag of tortilla chips on a large platter. Top with beef/beans topping, cheese sauce, & pico de gallo. Or - serve all ingredients in separate bowls & let everyone customize their own nacho plate.