In a large skillet, cook the chorizo, garlic, and cumin, stirring, over medium-high heat until the sausage is browned and the fat is rendered, about 5 minutes. Remove and drain on paper towels. To the fat in the pan, add the pinto beans, chili powder, and salt and cook over medium heat until warmed through, smashing slightly with the back of a heavy wooden spoon and adding water a teaspoon at a time if the beans get too dry. Remove from the heat.
Preheat the oven to 450 degrees F.
On a large, oval ovenproof platter or in a large baking dish, spread 1 layer of chips. Top with a layer of 1/2 of the beans, then 1/2 of the sausage, cheeses, onion rings, and chopped jalapenos. Repeat with another layer of chips, beans, sausage, cheese, onions and jalapenos. Bake until the cheeses are melted and the mixture is hot, 5 to 8 minutes. Remove from the oven.
In a small bowl, whisk together the sour cream and lime juice, with a pinch of salt. Drizzle over the nachos, garnish with cilantro, and serve immediately.
Yield: 4 servings