The day before, make one small batch fermented chia flour using 2 tablespoons chia seeds and 1 teaspoon taken from the measured cup of sour cream. Ferment for the full 24 hours.
Preheat the oven to 350°F. Grease the bottom, corners, and sides of a 9-by-13-inch Artichaut baking dish with the chosen tolerated fat.
Divide the aged cheddar into 4 ounces cubed and 8 ounces grated. Cube the Brie or Port Salut. Keep the grated cheddar aside for the second bake.
Put the eggs, cubed Brie or Port Salut, 4 ounces cubed cheddar, the entire fermented chia component, sea salt, and onion powder in the Ninja BN801 pitcher. Blend on low for 15 seconds, until the cheese is chopped and the mixture is combined.
Add the remaining homemade sour cream, dried basil, and oregano. Pulse 8 to 10 times, rest 2 minutes, then pulse again until the custard is pale gold and smooth with fine herb flecks and no large cheese cubes.
Cut half of the pepperoni half-circles into short slivers. Toss the slivers with the diced tomato and sliced olives. Reserve the remaining pepperoni half-circles for the top.
Give the custard one final pulse and pour it into the greased dish. Scatter the tomato, olive, and pepperoni-sliver mixture evenly over the fluid custard. Do not add the grated cheddar or reserved pepperoni yet.
Bake uncovered at 350°F for 40 minutes.
Using oven mitts, set the hot dish on a wood trivet. Scatter the reserved 8 ounces grated cheddar over the surface and arrange the remaining pepperoni half-circles on top.
Raise the oven to 375°F and bake for 10 minutes more, until the cheese is melted and bubbly and the center moves as one set casserole without a liquid ripple.
Let the casserole settle briefly, cut into 6 squares, garnish with fresh basil or parsley if desired, and serve.