Queso Fundido

Heat oil in 10-inch nonstick skillet over medium-high heat until shimmering. Add chorizo and cook, breaking up meat with wooden spoon, until browned, 3 to 5 minutes. Add onion and poblano and cook until vegetables are softened and lightly browned, 3 to 5 minutes. Transfer chorizo mixture to paper towel–lined plate.

Toss pepper Jack, Colby Jack, and cornstarch in microwave-safe 2-quart casserole dish until cornstarch lightly coats cheese. Stir in water and chorizo mixture until combined.

Cover with plate and microwave until cheese begins to melt around edges of dish, 1 to 2 minutes. Stir and continue to microwave, covered, until cheese is completely melted and just beginning to bubble around edges of dish, 1 to 3 minutes longer, whisking once halfway through microwaving (temperature of cheese should not exceed 180 degrees). Whisk and serve immediately.