Can be done a day or two ahead: Make the pine-nut cheese. Put the first 8 ingredients (yogurt through liquid smoke) in the blender and blend for 3 minutes on high, stopping to scrape down the sides as necessary.

Make the pine-nut cheese. Put the first 8 ingredients (yogurt through liquid smoke) in the blender and blend for 3 minutes on high, stopping to scrape down the sides as necessary.

Pour the mixture into a heavy-bottomed saucepan. Cook over medium heat, stirring constantly for about five minutes. It will start out lumpy and then become smooth and thick. Reduce the heat to low and cook 3 more minutes.

Pour the mixture into a glass bowl, using a spatula to clean out the saucepan. Smooth the top.

Let cool on the counter, then cover and refrigerate until firm.

Halve, peel, and thinly slice the onion. Bring a heavy saute pan or cast iron frying pan over medium heat. Add 1-2 T. olive oil and heat until it shimmers and tilt the pan until the oil covers the bottom evenly. When a drop of water sizzles, add the onions, stirring to coat. Cook for five minutes, stirring a couple of times, then turn down the heat to medium low and cook for about 30 minutes until a golden caramel color. If not using right away, store covered in the fridge.

When you are ready to make the dip: Preheat the oven to 375F/190C/gas mark 5. Spray an oven-proof round or square serving dish.

Drain the artichokes. If using frozen artichokes, let them thaw in a colander.

Put the artichokes, onion, and optional spinach in a food processor and pulse until finely chopped.

If the cheese is firm enough, grate it cheese using a box grater. (If not, just stir it in.) Mix the cheese with the onion-artichoke mixture in the sprayed serving dish, smoothing the top with a spatula.

Bake for 30 minutes until bubbly and golden. Serve immediately with crackers.