In a deep sauté pan or skillet, heat the oil over medium heat until shimmering. Line a plate with a paper towel.
Using tongs, dip one tortilla at a time into the hot oil, fold to form a taco shell, and cook for 3 minutes, until golden brown or crispy enough to hold the shape. Transfer the taco shell to the prepared plate. Repeat this process with the remaining tortillas and cool them to room temperature.
Meanwhile, in a double boiler, combine the milk chocolate chips and dark chocolate chips over medium heat. Heat them, stirring, until melted and smooth. If using the microwave, melt the chips in intervals of 10 to 20 seconds and stir to avoid burning the chocolate.
When ready to serve, stuff each taco shell with the ice cream and dip half of the taco shell in the melted chocolate. Top with the peanuts and eat immediately.