Add the olive oil, one tablespoon at a time, pulsing in between, until the pesto reaches the right thickness.
¼ cup olive oil
Spread 2 teaspoons of pesto on one side of one slice of bread.
2 slices bread
Top with the Gouda, then the browned ham, and sprinkle the toasted pine nuts over it.
1 slice Gouda cheese
Cover with the second slice of bread and place under the broiler until the sandwich is golden and the cheese has melted.
NOTES
1. Gouda: Regular Gouda melts beautifully here and has enough flavor to hold its own next to the pesto. No need to make it more complicated.2. Ham: Brown the ham first This small step adds a deeper, more roasted flavor. It makes the sandwich taste warmer and fuller.3. Pine nuts: Toast the pine nuts gently Keep the heat low. Pine nuts go from golden to burnt very fast, and nobody needs that kind of drama at lunch.4. Don’t overload the sandwich with pesto A thin layer is enough. Too much pesto can make the bread soft instead of crisp.5. Best bread to use: Choose bread that toasts well and keeps its shape. A sturdy white loaf works well, and sourdough is great too. Corn bread is a lovely extra tip because its slight sweetness works really well with the salty ham and savory pesto.6. Broiler, grill pan, skillet or sandwich maker: You can make this under the broiler, in a grill pan, fry in a skillet or in a sandwich maker.7. Leftovers: This sandwich is at its best hot and fresh, when the bread is crisp and the cheese is perfectly melted.