Preheat the oven to 400°F (200°C) to cook the bacon.

Place the bacon slices on a baking sheet lined with parchment paper and bake in the preheated oven for about 15 - 20 minutes or until crispy.

While the bacon is cooking, heat a skillet over medium heat with butter.

Add the diced onion and green bell pepper to the skillet and sauté until softened, about 3 - 4 minutes. (Consider preparing multiple omelets if preparing many servings.)

Add the sliced mushrooms to the skillet and cook for another 2 - 3 minutes until they start to brown.

Pour the beaten eggs evenly over the sautéed vegetables in the skillet.

Allow the eggs to cook undisturbed for a few minutes until the edges start to set. Lift up the edges of the omelet so that the uncooked egg flows underneath the omelet and cooks.

Sprinkle the diced tomatoes evenly over the eggs and top with torn Swiss cheese pieces.

Season the omelet with salt and pepper to taste.

Carefully fold the omelet in half and cook for another 1 - 2 minutes until the cheese melts and the eggs are cooked through.

Arrange the crispy bacon slices alongside the omelet.

Toss the arugula with a little olive oil, a squeeze of lemon juice, salt, and black pepper in a bowl.

Serve the garden omelet with bacon, arugula salad, and orange juice.