For the shallots: Place 1/2 cup water, the vinegar, sugar and salt into a small saucepan and bring to a simmer. Pour the mixture over the shallots and serrano in a bowl and stir to coat. Cool to room temperature, 15 to 20 minutes.
For the tri-tip: In a small bowl, combine the chili powder, sugar, parsley, garlic, mustard, sage, thyme and cayenne. Score the fat cap with 1/2-inch slits. Rub the tri tip with the spice mix, then cover and let it sit 2 hours to overnight.
Line a roasting pan with foil, place the woodchips on top and place on the stove over medium-high heat. Make sure the woodchips start smoking, it may take 6 to 8 minutes depending on how much water the wood absorbed. Place a roasting rack on top of the chips and line with another piece of foil, cutting slits in it to allow some of the smoke to escape. Place the tri tip on the foil-covered rack, then cover with a lid or seal tightly with foil. Smoke for 50 minutes. Let rest for 10 minutes before slicing.
For the sandwich build: Schmear your toasted and buttered roll with some smoked cauliflower. Top with the beautiful tri tip, and garnish with the pickled shallots.
Fill a large saucepot with salted water and bring to a rolling boil. While the water comes to a simmer, prepare an ice bath.
Drop the cauliflower into the simmering water and blanch until slightly tender, 3 to 5 minutes. Remove and immediately plunge into the ice bath. Drain and dry completely.
Line a roasting pan with foil, place the wood chips on top and place over medium-high heat. Make sure the woodchips start smoking; it may take 6 to 8 minutes, depending on how much water the wood absorbed. Place another piece of foil over the smoking chips and a roasting rack on top. Place the cauliflower on the rack, cover with a lid or seal tightly with foil, and smoke for 3 minutes.
Remove the cauliflower from the smoker and transfer to a food processor along with the ricotta, garlic and melted butter. Process until almost smooth, and season with salt and pepper.