Preheat your oven to 180°C (160°C fan). While it heats, take your 800g frozen berries and tip them straight into a 20x30cm baking dish. Don't bother thawing them — the heat will do the work. You'll hear a gentle clatter as the frozen berries settle against the dish.

Sprinkle 60g of erythritol, 2 tablespoons of chia seeds, 1 teaspoon of vanilla extract, and 1 tablespoon of lemon juice evenly over the frozen berries. Stir everything gently with a spatula until the berries are lightly coated and you can see a faint sheen of vanilla and lemon. The berries will still look frosty, but that's fine.

In a separate, large mixing bowl, combine 150g almond flour, 50g desiccated coconut, 50g chopped almonds, 1 teaspoon ground cinnamon, and ¼ teaspoon salt. Stir with a fork until the mixture looks uniform — a warm, golden-brown colour with flecks of white coconut.

Add the 100g of cold, cubed butter to the dry ingredients. Use your fingertips to rub the butter into the flour mixture until it resembles coarse breadcrumbs. You'll feel the butter soften against your fingers, and the mixture should clump slightly when squeezed. The texture should look like damp sand with some larger, nutty pieces throughout.

Spoon the almond crust topping evenly over the berries. Don't press it down — leave it loose and crumbly so it crisps up in the oven. You'll see small peaks and valleys of topping across the berry surface.

Bake for 35-40 minutes. At the 25-minute mark, the kitchen will smell deeply of toasted almonds and sweet, jammy berries. The topping should be a deep golden brown, and you'll see the berry juices bubbling up around the edges of the dish. If the topping browns too quickly, tent loosely with foil for the final 10 minutes.

Remove from the oven and let it rest on a wire rack for at least 10 minutes. During this time, the chia seeds will continue to absorb the berry juices, thickening the filling to a jammy, spoonable consistency. The topping will set into a crunchy crust.

Spoon into bowls and serve warm. If you're adding cream or yoghurt, pour it directly over the crisp so it melts into the warm berries. The contrast between the cold cream and the hot, bubbly filling is the moment it all comes together.