Preheat oven to 350F (180C). Toast the almonds for 7-8 minutes or until toasty and fragrant. Set aside to cool.

In a food processor, add the almonds, sage, garlic, lemon juice, zest and sea salt. Process until small bits form. With the processor running, pour in the olive oil in a steady stream. Process for another 30 seconds or until a chunky paste forms.

Store in a lidded container for up to 4 days in the refrigerator or freeze for up to 3 months.

Preheat a cast iron skillet on medium low while lightly buttering two slices of bread on one side each. In the skillet, place the butter sides down into the pan and spread about 1 1/2 Tbs of pesto on each side. Divide about 1/3 C (33g) of cheese total, between both slices of bread. With both slices of bread, cheese side up, grill on medium-low with lid on for four minutes (set a timer). Remove from heat and let sit, lid on, for an additional three minutes (again, set a timer) - but check after two minutes just to make sure the toast isn't too toasty!

Using a spatula, remove each side carefully from the pan and put the sandwich together. Cut and serve immediately.

If serving a few at the same time, place in a warmed 200F (93C) oven while grilling the other sandwiches.