Preheat your oven to 400°F and lightly coat a small ceramic baking dish with avocado oil to ensure easy removal.
Place the frozen tater tots on a baking sheet and par-bake for 10 minutes to ensure they stay structurally sound and crispy within the casserole.
While the tots bake, dice the bacon and chicken breast into uniform half-inch pieces for even cooking.
In a skillet over medium heat, fry the bacon until the fat has rendered and the edges are crisp, then set aside on a paper towel.
Using the same skillet, sauté the chicken and diced red onion until the chicken is golden and the onions have softened.
Drizzle the maple syrup over the chicken, stirring constantly for 2 minutes to create a thick, amber glaze that coats every piece.
Layer the par-baked tater tots into the bottom of your baking dish, followed by the maple-glazed chicken, bacon, and fresh spinach.
In a separate bowl, vigorously whisk the eggs with sea salt and black pepper until frothy, then pour over the layers in the dish.
Bake the casserole for 18-22 minutes until the center is firm to the touch and the edges are a deep golden-brown.