Use a microwave-safe mug or cup that is just slightly smaller than the diameter of the english muffin. Gently press the english muffin to the bottom of the mug—it should be a tight fit. Then spray the edges of the mug with non-stick cooking spray. Sprinkle half the shredded cheese over the english muffin.
In a separate small bowl, whisk together the egg, yogurt, pico de gallo and a pinch of salt until frothy. Pour over the english muffin. Top the egg mixture with the chorizo and remaining cheese.
Microwave on high heat for 1 1/2-2 minutes, until puffy and cooked through. Then either garnish and serve in the mug, or pop out of the mug for a breakfast-on-the-go.