Heat olive oil in a medium skillet over medium heat. Sauté leeks until softened and glossy, about 5 - 6 minutes. Add garlic and jalapeño, saute for 1-2 minutes more. Remove from heat, season with salt and pepper.
Place half of the leek mixture into a food processor with peas, mint, lemon juice, 1/4 tsp salt and pepper. Pulse until a chunky, soft mixture forms. You want to be able to see texture in the peas, not create a puree.
For the toast, there are two delicious options: either toast in the toaster and add a thin spread of mayonnaise to each and top with pea mixture and remaining leeks.
OR! The bonus, extra decadent option: Fry the toast. Yep, fry it. Add another generous drizzle of olive oil to the pan, over medium high heat and place the bread in the pan - 2 slices at a time - until golden on each side. Then top with peas and remaining leeks.
Note about jalapenos:the heat level varies significantly in jalepenos. Some have real heat, others are more like bell peppers. So I always take a little nibble before I cook with them. If the flesh is truly spicy, you can seed it and use less, to your taste. If the flesh isn't spicy, keep the seeds...and use more. I like a bit of a kick with this recipe