Preheat the oven to 425°F (220°C).
Heat a large skillet over medium-high heat and add the ground chicken. Cook, breaking the meat up with a spatula, until it begins to brown, about 3–4 minutes.
Add the chopped onion and chopped poblano or bell pepper to the pan. Continue to cook and stir until the vegetables are softened and the chicken is cooked through, about 4–5 minutes.
Stir in the chopped garlic, dried oregano, ground cumin, cayenne, and salt and black pepper to taste. Add 1/2 cup water and cook for about 5 minutes until the mixture is fragrant and slightly reduced. Stir in the chopped pepperoncini, then remove the skillet from the heat and let the filling cool slightly.
Warm the corn tortillas in the microwave in 30-second intervals until pliable, working in batches. Lightly coat one side of each tortilla with olive oil.
Spoon about 2 tablespoons of the chicken filling down the center of each warmed tortilla. Roll each tortilla tightly and place seam-side down on a baking sheet in a single layer.
Bake the taquitos for 10 minutes, until starting to crisp. Remove from the oven and pour the red enchilada sauce evenly over the taquitos. Sprinkle the shredded Swiss and pepper jack cheeses over the sauced taquitos.
Return the baking sheet to the oven and bake an additional 10 minutes, until the cheese is melted and bubbling and the edges are crisp.
Meanwhile, make the pineapple-cilantro salsa: in a bowl combine the diced pineapple, chopped cilantro, chopped jalapeño, and lime juice. Stir to combine and season with salt if desired.
Serve the baked cheesy taquitos topped with chopped or sliced avocado, a dollop of Greek yogurt, and the pineapple-cilantro salsa. Squeeze lime over the top if desired.
