Prepare the Lump Crab: If using canned crab meat, drain and gently pick through it to remove any shell fragments. For fresh lump crab meat, ensure it's cleaned and ready to use.

Preheat the Oven: Preheat your oven to broil

Prepare queso: To a small skillet or pot, melt butter and saute onions, peppers and garlic until fragrant, about 2 minutes. Then add milk and seasoning taste. Turn heat to low and begin adding cheese a little at a time until fully melted. Once cheese is melted, add cornstarch and thicken queso, bring to a low simmer and once thick, turn off the heat.

Assemble the Nachos: On a large baking sheet or oven-safe platter, arrange a single layer of tortilla chips. Sprinkle the shredded Monterey Jack and cheddar cheese evenly over the chips. Then, distribute the queso and lump crab meat on top of the cheese. You can leave excess queso for later dipping if desired.

Place the assembled nachos in the preheated oven and broil until cheese is melted and everything is heated through, about 1 to 2 minutes

Add Toppings: Add Sour Cream, more onion, diced tomatoes, and, if desired, sliced jalapeño peppers over the crab meat.

Garnish and Serve: Once out of the oven, drizzle the sour cream over the nachos, sprinkle with chopped cilantro, and garnish with lime wedges for that zesty kick.