Start at least 3 days in advance; cover lentils with about an inch of water and let sit overnight.

The next day strain and spread lentils out in the strainer, giving them as much room as possible. Set the strainer over a plate and cover with a clean kitchen towel. Leave at room temperature.

Rinse lentils at least 3 times a day for at least 2 days or until they start to sprout. Continue rinsing and leave them covered at room temperature for up to 5 days, depending on how large you'd like the sprouts to be.

Transfer to a resealable plastic bag and refrigerate. Sprouted lentils will keep for up to 5 days in the refrigerator.

Heat oven to 425°F and arrange rack in the upper third.

Combine sweet potatoes, olive oil, and spices in a large bowl. Lay in a single layer on a baking sheet and roast until just tender, about 15 minutes.

Meanwhile, make the salsa. Place jalapeños and unpeeled garlic cloves in a dry comal or skillet over medium-high heat. Cook until charred on all sides (garlic will take less time so remove that first).

Remove garlic peel and the stems from the jalapeños. Cut jalapeños in half and remove seeds if you'd like it less spicy.

Place charred vegetables in a blender with yogurt, cilantro, olive oil, vinegar, and salt and blend on high until smooth. Taste and add more salt or vinegar as needed.

To serve, toss sweet potatoes with cilantro and sliced spring onions then divide between the warm tortillas and top with sprouted lentils. Drizzle with salsa and enjoy!