Chop almonds, walnuts, sunflower seeds, and pumpkin seeds into appropriate sizes.
Place oatmeal in a large bowl and add the prepared nuts and seeds.
Add stevia or erythritol to adjust the sweetness.
Melt coconut oil and mix it evenly with the ingredients.
Line an oven pan with parchment paper and spread the mixed ingredients flat.
Bake in a preheated oven at 160°C for 20 minutes.
Stir the mixture once during baking for even cooking.
Cool completely and store in an airtight container.