Toast the slices 2–3 minutes per side in the hot pan until golden brown and crisp at the edges. Alternatively, toast in a toaster or under a broiler to your desired crispness. Keep warm.

Avocado-feta mousse

Prepare avocados

Halve and pit the avocados. Scoop flesh into a food processor or a bowl for hand-mashing.

Add crumbled feta, Greek yogurt, lime juice, minced garlic, olive oil, salt and pepper to the avocado.

Pulse in the food processor until smooth and mousse-like, scraping down the sides. If mixture feels too thick, add cold water 1 tablespoon at a time (up to 2 tbs) to reach a spreadable, airy consistency. Taste and adjust salt and lime as needed.

Caramelized onions

Cook onions low and slow

Heat a medium skillet over medium-low heat. Add butter and olive oil. When the butter melts, add the thinly sliced onion and sprinkle with salt and sugar. Stir to coat.

Cook, stirring occasionally, for 20–30 minutes until onions are soft, deep golden and caramelized. If the pan becomes too dry, add a teaspoon of water to deglaze. In the last minute, stir in balsamic vinegar if using, then remove from heat and set aside.

Toppings & garnish

Prep vegetables and seeds

Slice cucumber thinly and halve cherry tomatoes. Roughly chop cilantro. Lightly toast mixed seeds in a small dry skillet over medium heat for 1–2 minutes until fragrant; remove immediately to avoid burning.

Assemble toasts

Spread a generous layer (about 2–3 tbs) of avocado-feta mousse on each warm sourdough slice. Pile a small handful (about 2 tbs) of baby arugula on top of the mousse. Add 1–2 tablespoons of caramelized onions per slice, then arrange cucumber slices and cherry tomato halves attractively.

Scatter chopped cilantro and toasted seeds over each toast. Finish with a light drizzle of extra virgin olive oil, a squeeze of fresh lemon juice, a pinch of sea salt and a sprinkle of red pepper flakes to taste.

Serve immediately while bread is still crisp.