Over medium heat, toast the almonds and walnuts in a dry skillet, without adding any oil, for 3–4 minutes, stirring constantly until fragrant and lightly golden. Remove from the skillet and set aside to cool.
Add the sesame seeds to the skillet and toast over medium heat, stirring constantly until they turn lightly golden and release their nutty aroma. Keep a close eye on them, as sesame seeds can burn quickly. Remove from the skillet and set aside to cool.
In the same skillet, lightly toast the pumpkin seeds over medium heat, stirring frequently. As they heat up, some seeds may pop slightly—don't worry, this is perfectly normal! Continue stirring for 2–3 minutes, until the seeds turn golden brown and release their nutty aroma. Remove them from the skillet promptly to prevent burning, and set aside to cool.
In a food processor fitted with a blade, combine the toasted almonds, walnuts, sesame seeds, pumpkin seeds, fennel seeds, cumin powder, coriander powder, and sea salt.
Pulse the mixture until the ingredients are well combined and coarsely ground. Be careful not to overprocess—you don’t want a fine powder! The ideal texture should resemble coarse breadcrumbs, with a delightful crunch from the nuts and seeds.
Transfer the dukkah to a clean, airtight glass jar and store it in a cool, dry place at room temperature for up to 3 weeks. Happy eating!