Make the salsa: In a large pot, boil one quart of water and add tomatillos. Boil until tomatillos are soft. Once soft, remove from water. In blender, add Hatch chile, tomatillos, garlic, onion, salt and 1/2 cup water. Blend for 15 seconds or until smooth.
Make the filling: In a large skillet, heat oil over medium heat. Add shrimp and cook until pink. Add potatoes and squash and salt to taste. Incorporate ingredients by stirring rapidly. Cover and reduce heat to medium low. Stir periodically until shrimp is completely cooked and potatoes are soft. Remove from heat.
Heat corn tortillas over stove on a skillet or comal.
To assemble: Place 2 tablespoons of shrimp mixture in the middle of tortilla and roll. Place rolled tortilla with stuffing on a baking tray. Continue to assemble enchiladas. Pour salsa over assembled enchiladas and place in the oven for 7-10 minutes to warm up the salsa.
Plate your enchiladas. Garnish with radish matchsticks and crumbled Cotija cheese. Enjoy with white rice.