Have all the prepped ingredients easily accessible to assemble nachos.
Preheat the oven to 350 degrees F.
In a small saucepan over low heat, cook refried beans until they are loose enough to spoon onto nachos. On a large ovenproof platter, spread out a layer of tortilla chips and quickly put a teaspoon of hot refried beans on each chip. Working quickly, sprinkle with some onions, jack cheese, and jalapeno slices. Spoon on chili and top that with Cheddar. Repeat this layering process until ingredients are used up. Save some of the jalapeno slices for garnish. Place platter in the oven and bake until cheese has melted, about 5 to 10 minutes. Remove from oven and place on a trivet or heatproof surface. Top nachos with sour cream, green onions, diced tomato and jalapeno slices and serve hot.