Heat olive oil in a large saute pan over medium-high heat. Add the tilapia cubes and cook 1 to 2 minutes, turning and stirring to cook throughout until the fish flakes easily with a fork. Remove from heat and transfer the fish to a separate plate to cool.
Saute' peppers and onion until soft. Broil until cheese melts. Serve immediately.
While the fish is cooking, spread the chips out evenly on a large baking sheet. Top with fish, peppers, jalapeno, onions, and cheeses.
Place the sheet in the oven under the broiler until the cheese is melted, about 1 minute. Do not step away, they will burn quickly.
Remove from the oven, then top the chips evenly with additional toppings if desired or serve as is.
Finish with your favorite toppings: lettuce, sour cream, tomatoes, cilantro, salsa, etc