Reserve ½ teaspoon of the homemade fajita seasoning to add at the end of the recipe. Then generously sprinkle the rest of the fajita seasoning on both sides of the snow goose breasts and use your fingers to press it in. You can cook the goose breasts right away at this point, but if you have time to place them in a Ziploc bag or plastic container and put them in the refrigerator for at least 4 hours or overnight, you'll end up with a lot more flavor in the end.
Heat a large skillet over medium heat and lightly coat it with 2 tablespoons of olive oil or canola oil. Sear the snow goose breasts for about 5 minutes on each side until they reach an internal temperature of 130 degrees F using an instant read meat thermometer. Then transfer them from the pan to a cutting board and let them rest while you sauté the vegetables.
While the goose breasts are cooking, cut the onions and bell peppers into thin slices. Then while the cooked breasts are resting, sauté the vegetables in the same skillet over medium high heat for about 5 minutes until caramelized.
Using a sharp knife, thinly slice the goose breasts and place them back into the skillet, squeeze fresh lime juice on top, sprinkle everything with the remaining ½ teaspoon of fajita seasoning, and stir everything together.
Serve immediately with tortillas and other toppings like guacamole, pico de gallo, and fresh cilantro.