Heat a large skillet on medium-high heat and melt the butter. Once bubbling, add yellow onion and cook down for 5-6 minutes or until translucent. Stir in the garlic, mushrooms and season with nutritional yeast and salt and pepper. Cook the mushroom mixture on medium heat, stirring often until the mushrooms are tender but the moisture in the pan has evaporated completely (this may take up to 10-1 5 minutes). Stir often to avoid burning. Stir in thyme and honey and cook for 2 minutes or until the mixture is well combined and well coated. Taste test for salt and flavour.
Transfer the mushroom mixture to a food processor along with the feta cheese and pulse for 10-15 seconds. Transfer mixture to a large bowl.
Time for the phyllo prep! Have your 4 tbsp. melted butter ready with a brush to gently coat phyllo. Make sure you have a spray water bottle close by.
Gently placing one sheet of phyllo onto a clean cutting board. Coat the whole sheet with melted butter, using your brush. Add another sheet on top and repeat covering the sheet with melted butter. Add a third sheet on top and brush the third sheet with butter. Using a very sharp knife cut through the stack of three phyllo sheets lengthwise, four times. You should be able to see where you are going to place your filling now (at either end of the cut phyllo).
Using a teaspoon, scoop a heaped teaspoon onto the ends of one side. Start by folding one bottom corner of the phyllo and meeting it with the opposite top corner and continue folding until you reach the top and have created a triangle.
Repeat steps till you have around 32 Mushroom Bites! Before baking place the Mushroom Bites onto a plate and store in the freezer for 30 minutes.
Preheat your oven to 400F. Once they’ve cooled, place onto the parchment-lined baking sheets and brush with melted butter one more time. Bake for 20-25 minutes or until golden brown and perfectly crispy!
TIP - Pastry cooks best when cold so try to keep the sheets as cool as possible. You also want to keep the pasty moist, so use a spray bottle to occasionally spray the phyllo. All it needs is a touch, one spray each time with do!