Bring a large pot of water to boil and cook pasta 7 – 8 minutes. You want it a little under done at this point because it will continue to cook in the cheese sauce. Drain and rinse under cold running water to stop the cooking.

In the same pot that you cooked the pasta in, melt 2 tablespoons of butter over medium heat. Stir in onions and jalapenos. Cook just until softened, about 3 minutes.

Return the macaroni to the pan and reduce heat to medium low. Stir in the remaining butter. Once butter has melted stir in milk, eggs, cheddar and jack cheese, kosher salt, cumin and chili powder. Sauce will be very thin at this point. Cook for 10 – 15 minutes or until the sauce thickens, stirring frequently. Do not allow the sauce to boil or it will curdle. Remove from heat and let stand 5 minutes. Let stand a little longer if the sauce still appears a little thin. Stir and spoon into bowls. Top each bowl with diced tomatoes and avocados.